Prediction Market Surveillance and Abnormal Trading Detection: A Layered Defense Against Insider Trading, Wash Trading, Sybil Attacks, and Settlement Window Sniping

InfrastructurePrediction Market٤ أغسطس ٢٠٢٦

Prediction markets (Prediction Market) have moved from crypto-native experiments to mainstream financial products between 2024 and 2026. Platforms such as Polymarket, Kalshi, Manifold, and Limitless have accumulated billions of dollars in trading volume on high-profile events spanning political elections, sports, macroeconomics, and crypto prices. With this scale, prediction markets have also become a high-value target for market manipulation—yet they are far easier to manipulate than spot or perpetual-futures markets.

Why are prediction markets more manipulable? Three root causes: 1) settlement is binary, so manipulation gains scale non-linearly; 2) liquidity is thin (especially on long-tail events), where a single $50,000 order can push a price from 0.30 to 0.70; 3) information asymmetry is natural—a politician, a player's family member, or a public-company executive can build a position in the minutes before the information goes public and capture near-100% insider return. These three features combined turn prediction markets into a hotspot for insider trading, wash trading, Sybil attacks, and settlement-window sniping.

For a team running a prediction market, surveillance is no longer a "nice to have"—it is a survival baseline. A platform that is regulatorily found to "tolerate manipulation" faces fines, license revocation, and user churn; a platform that the market perceives as having "distorted data" loses information traders and dies a natural death.

This article starts from the financial-structural reasons why prediction markets are manipulable, walks through the manipulation landscape (insider trading, wash trading, Sybil, spoofing, marking the close, oracle attacks), and presents a layered detection architecture (rules engine + statistical anomaly detection + graph algorithms + machine learning) with full engineering implementation. It covers alert tiering, human review workflows, enforcement actions (position limits, order cancellation, market void, settlement delay), dispute resolution with UMA-style optimistic oracles, explainability and evidence chains, regulatory reporting across Southeast Asia (SC Malaysia, BAPPEBTI/OJK Indonesia, SEC Thailand, MAS Singapore), and engineering architecture with Flink/Kafka and graph databases, ending with SoonTech's productized solution. Whether you are a product lead, risk director, compliance head, or CTO architect of a prediction market, after reading this article you will have a complete framework that can be implemented directly.

1. Why Prediction Markets Are Inherently Easier to Manipulate

1.1 Three Root Causes

Cause 1: Settlement is binary and gains are non-linearly amplified. On a spot or perpetual-futures market, pushing the price up by 1% only yields a 1% spread. On a binary Yes contract, pushing the price from 0.30 to 0.90 means "position cost 0.30, potential settlement 1.00, return 200% on top of 3x leverage." A manipulator using the same capital can earn several multiples of the operation return that a spot manipulator can.

Cause 2: Liquidity is thin and a single order can set the price. Mainstream long-tail event markets (e.g., "Will the Democrats flip the 7th district in the 2026 US congressional election?") may have only $20,000–$30,000 of resting depth. A $10,000 market order can push the price by 30–50 basis points. Headline platforms such as Polymarket and Kalshi may see $50 million daily volume on hot events, but on 95% of events daily volume is below $50,000.

Cause 3: Information asymmetry is natural and hard to eliminate. The outcomes of prediction-market events are typically known by an extremely small number of people—a congressperson's voting intent, a sports team's starting lineup, a leaked economic data point. These people can build positions 5–10 minutes before the information goes public and capture near-100% insider return. In traditional finance, similar "informed trading" is caught and investigated by the SEC's SMARTS and FINRA's surveillance; in prediction markets, the protocol layer can barely distinguish legitimate research from insider trading when the "last-mile" information advantage is at issue.

1.2 Comparison with Spot Exchanges

DimensionSpot / PerpetualsPrediction MarketReturn curve

Linear, 1% spread = 1% return

Non-linear, 0.30→0.90 = 200% return

Liquidity

Top pairs usually $50M+ 24h depth

95% of events < $50K daily volume

Settlement

Continuous pricing, close at any time

Binary / discrete outcome, settles at expiry

Information source

Large public data + on-chain metrics

Very few insiders + public news

Market-making incentive

HFT, MMs compete fiercely

No pros on long-tail markets

Post-manipulation tracing

Mature regulators, market-surveillance units

Regulatory framework still being built

1.3 Real Cost and Potential Gain of Manipulation

A set of numbers to illustrate why prediction markets are a "low-cost, high-return" attack target. Suppose the manipulator has non-public information, the event resolves in 30 minutes, the current Yes price is 0.40 (the market has not yet priced in the true result 0.95), and the manipulator spends $50,000 buying Yes. At settlement, they get $50,000 / 0.40 = 125,000 Yes shares, redeem at 1.00 = $125,000, net profit $75,000, 30-minute return 150%. Even subtracting 5% slippage, 2% fees, and 10% probability of being blocked by surveillance, the expected return still exceeds 50%.

This is why, for a $600M prediction market, attackers will spend hundreds of thousands of dollars on research, wash trading and manipulation: as long as they succeed once, the return covers a year of cost. When SoonTech builds surveillance solutions for Southeast Asian clients, we repeatedly emphasize that "surveillance ROI is not a cost center, it is the platform's survival baseline."

2. Manipulation Landscape: From Insider Trading to Settlement Window Sniping

2.1 Taxonomy of Manipulation Techniques

TechniqueTypical BehaviorSeverityRegulatory StanceInsider trading

Building a position before public information

Extreme

Explicitly illegal in most jurisdictions

Wash trading

Affiliated accounts trade back and forth

High

Explicitly illegal in most jurisdictions

Self-match

Same account hits itself

High

Explicitly prohibited by platform rules

Multi-account linkage / Sybil

One natural person controls many accounts

High

Violates platform ToS

Spoofing

Large orders placed and cancelled to fake depth

Medium

Explicitly defined by US CFTC

Fake liquidity / Layering

Multi-level orders to fake depth

Medium

Watched by CFTC / FCA

Marking the close

Concentrated buying in the minutes before settlement

Extreme

Classic market manipulation

Incentive arbitrage / Airdrop farming

Platform rewards exploitation

Medium

Violates ToS

Oracle / resolution-source manipulation

Attacking or bribing data sources

Extreme

Criminal offense

Rumor manipulation

Fake news aligned with a position

High

Illegal in most jurisdictions

2.2 The "Golden 5 Minutes" of the Settlement Window

The biggest difference between prediction markets and spot / perpetual contracts is the "Resolution Window"—the last few minutes to a few dozen minutes before the event expires are the highest-incidence period for attacks. Three reasons:

  1. Liquidity evaporates quickly (other traders have closed or are观望);
  2. Public information has not yet been fully digested (official announcements / data releases lag);
  3. The manipulator already holds the information and waits for the "last moment" to maximize return.

In production environments, SoonTech observes that about 68% of clearly abnormal trading concentrates in the last 60 minutes before event expiry, and 42% concentrates in the last 5 minutes. The surveillance system must enter "high-pressure mode" during the resolution window—more sensitive thresholds, denser alerts, higher-priority human intervention.

2.3 The Industrialization of Manipulators

After 2025, prediction-market manipulation is no longer a "single person operating manually" workshop-style attack. We observe three industrialization trends:

  • Bot swarms: attackers use scripts to control dozens to hundreds of accounts simultaneously, coordinating positions and timing;
  • Information pre-positioning: recruiting "information brokers" on Twitter, Telegram groups, and Discord channels, sharing profits by result;
  • Cross-platform synchronization: the same information is used to build positions synchronously on Polymarket, Kalshi, Limitless, Opinion, etc., dispersing risk.

This requires the surveillance system to perform association analysis on both the "account group" and "cross-platform" dimensions—single-account threshold alerting is far from sufficient.

3. Insider Trading Detection Models

3.1 Three Characteristics of Insider Trading

The core difference between prediction-market insider trading and spot-market insider trading lies in "price convergence speed." After public information is released, a prediction-market price should converge rapidly toward 0 or 1. If before the public information release, the price has already shown a "directional drift" consistent with the final result, and the accounts that built the position have "pre-association evidence," insider trading is highly suspect.

Characteristic 1: Pre-event drift. The price shows a directional movement exceeding a threshold (e.g., 10bp) within 60 minutes before public information release, and the direction is consistent with the final result.

Characteristic 2: Time correlation. The timing of the drift is highly correlated with "when the information source becomes available." For example, a basketball starting lineup is announced 30 minutes before tipoff, but some accounts have already built positions 60 minutes before tipoff.

Characteristic 3: Account clustering. Multiple accounts build positions in the same direction at similar times, and there is association evidence (device / IP / funds / behavior similarity) among them.

3.2 Feature Engineering: Insider Trading Signal Table

FeatureMeaningSuggested ThresholdWeightpre_event_price_drift

Max single-direction price move in last 60 min

> 10bp

0.20

volume_spike_ratio

Volume in last 30 min / historical same-period average

> 5x

0.15

account_count_cluster

Number of accounts building position in the same direction

> 5

0.15

info_source_timing

Gap between information source public time and position building

< 30 min

0.20

pnl_to_volume_ratio

Account PnL / volume

> 0.30

0.10

account_age

Days since account registration

< 7 days

0.05

device_reuse_count

Number of other accounts using the same device fingerprint

> 1

0.10

cross_platform_match

Same device/IP has done similar behavior on other platforms

yes

0.05

The weight sum is 1.0. The per-account score = Σ(normalized feature value × weight). A score > 0.65 triggers a high-tier alert.

3.3 Time-Series Anomaly Detection

In pre-event drift identification, single-point threshold alerts easily miss "slow accumulation" manipulation. We recommend time-series anomaly detection:

  • CUSUM / Page-Hinkley: detect cumulative shifts in price mean / variance, sensitive to slow drift;
  • Prophet / STL: model the "normal" periodic fluctuation of price (pre-game vs in-game, before/after macro releases), detect residual anomalies;
  • Bayesian change-point: online detection of change points in price distribution, suited to low-latency scenarios.

3.4 Time Alignment with Event Sources

The surveillance system must maintain an "event source timeline":

  • A basketball game: tipoff, lineup release, scoring times;
  • A political election: debate, voting close, result announcement;
  • A macro data point: release time (in official time zone).

Each position-building event is aligned to this timeline, and the "time difference to the nearest event source" is computed. If multiple accounts build positions 30+ minutes before a high-insider-value event source (starting lineup, internal vote, economic data) becomes public, the insider-trading probability rises significantly.

4. Wash Trading and Self-Match Detection

4.1 Definition and Harm of Wash Trading

Wash trading is when accounts trade with each other to manufacture fake volume and prices. In prediction markets, wash trading usually serves two purposes:

  1. Airdrop farming / incentive arbitrage: platforms reward volume, and wash trading can fake "real user behavior" at zero (or slightly negative after fees) cost;
  2. Manipulating price / liquidity perception: faking "active market" to lure other traders, or pushing the market-maker quote toward the manipulator's target.

Self-match is a special form of wash trading—accounts under the same controller trading with each other, or the same account hitting itself (in a matching system that supports dual-side positions).

4.2 Detection Features

FeatureMeaningSuggested Thresholdself_match_rate

Counterparty volume from affiliated accounts / total volume of the account

> 30%

round_trip_pnl

Total PnL of closed-loop trade pairs

near 0 (±0.5%)

time_to_close

Time from position open to close

< 5 min

price_unchanged

Mid-price change before and after trade

< 0.5%

volume_to_unique_accounts

Total volume / unique counterparty accounts

> 10x

round_trip_count

Closed-loop trade count of same account group in 24h

> 5

cross_market_correlation

Synchronized wash trading across markets

highly correlated

Self-match rate = counterparty volume from affiliated accounts / total volume of the account. When it exceeds 30%, a medium alert is triggered.

4.3 Closed-Loop Detection Algorithm

Closed-loop detection (Round-Trip Detection) tracks each account's "buy-hold-sell" sequence, identifying "A sells to B, B sells back to A" or "A→B→C→A" cycles. We use graph algorithms:

  1. Build a directed graph of account × time, each edge is a "sell" action;
  2. Detect all cycles of length ≤ 5 (short cycles significantly more than long cycles = suspicious);
  3. For each cycle, compute total PnL, price drift, duration, output a suspicion score.

Known affiliates (same KYC ID, same device fingerprint, same on-chain address cluster) are weighted higher. For unrecognized but similar accounts, graph embedding is used for candidate clustering, followed by human review.

4.4 Low-Cost Variants of Wash Trading

Industrialized wash trading does not leave obvious "A→B→A" patterns, but uses more complex structures:

  • Relay wash: A→B→C→D→E, A receives 5% spread profit, B–E each receive 1%, but the capital eventually returns to A's controlled on-chain address;
  • Time offset: A sells to B at T0, B sells to C at T0+10, C sells to A at T0+20, three trades at almost identical prices;
  • Cross-market wash: A sells outcome_1 to B in market X, B sells outcome_1 to C in market Y, C sells outcome_1 to A in market X.

These variants require more complex graph algorithms (account-market-time heterogeneous graphs) and behavioral sequence models (Transformer) to detect.

5. Multi-Account Linkage and Sybil Attack Detection

5.1 Association Dimensions

In production, SoonTech uses five dimensions for account association, with weights tuned by anti-fraud expert labels:

DimensionSignalWeightExampleDevice fingerprint

Device ID, UA, screen resolution, fonts, canvas fingerprint

0.25

Same phone controls 10 accounts

IP and network

IP, IP segment, ASN, Wi-Fi MAC, VPN/Tor exit

0.20

5 accounts under same home Wi-Fi

Funds flow

Deposit on-chain addresses, withdrawal on-chain addresses, on-chain behavior graph

0.25

Multiple accounts funded from same address

Behavior similarity

Trade time pattern, order pattern, slippage tolerance, UI operation rhythm

0.15

Accounts controlled by the same script

KYC and metadata

ID number, phone, email, bank card, referrer

0.15

Same ID opens multiple accounts

Association score = Σ(normalized dimension value × weight). Score > 0.70 is judged as highly associated (one person multi-account), 0.50–0.70 as suspiciously associated.

5.2 Device Fingerprint Implementation Details

Device fingerprinting cannot rely only on IP or cookies; it must combine multi-dimensional signals:

  • Hardware layer: screen resolution, pixel ratio, GPU model, CPU cores, memory, battery;
  • Software layer: UA, language, timezone, installed fonts, Canvas/WebGL render fingerprint, AudioContext fingerprint;
  • Behavior layer: mouse trajectory, keyboard rhythm, click pressure (mobile), gyroscope (mobile);
  • Network layer: IP, ASN, Wi-Fi BSSID (mobile), IP segment, TCP fingerprint.

SoonTech's device fingerprint SDK achieves 99.5% same-device recognition stability on mobile (same phone, multiple App opens remain stable), and cross-device recognition (one person, multiple devices) is supplemented by behavior similarity.

5.3 On-Chain Address Clustering

The on-chain versions of prediction markets (especially those based on Polygon, Base, Arbitrum) have a large number of deposit/withdrawal addresses, and address clustering is a "gold mine" for account association:

  • Common spending: multiple addresses as inputs of the same transaction, likely under same control;
  • Change address: change pattern recognition (one output of a transaction is much smaller than the others, and has not been spent);
  • Exchange hot addresses: withdrawal from the same exchange to multiple platform addresses;
  • Mixer labels: addresses with privacy protocols (Tornado Cash, Railgun) have special labels;
  • NFT / social graph: NFT holdings in wallets, on-chain social relations as auxiliary signals.

SoonTech partners with Chainalysis, Elliptic, TRM Labs and other on-chain analytics providers, and has built in-house address clustering models covering 30+ major chains and L2s.

5.4 Behavior Similarity

Behavior similarity is used to identify accounts controlled by the "same script / same gang". Common features:

  • Time pattern: distribution of trading hours, statistics of active duration (same script usually active in fixed time windows);
  • Order pattern: distribution of order price deviation from mid, cancellation rate, time from cancel to fill;
  • Trading rhythm: distribution of time intervals between adjacent trades, distribution of order sizes;
  • Error recovery: retry pattern after network failure, API call signatures.

We use an autoencoder for behavior embedding; similar accounts have significantly smaller distances in the embedding space than unrelated accounts.

5.5 The Industrial Chain of Sybil Attacks

Since 2025, Sybil attacks on prediction markets have formed an industrial chain:

  • Account farms: batch register accounts, bind phone numbers, pass face recognition (some platforms), nurture accounts;
  • Device farms: group-controlled phones/tablets, emulators, device-mutation tools;
  • Funding channels: top up multiple accounts through OTC desks, OTC, PayPal/bank accounts;
  • KYC bypass: use "white hats" in Southeast Asia, Africa, South America to pass face recognition on behalf;
  • Decision coordination: coordinate order timing, position, cancellation rhythm through Telegram groups, encrypted chat.

SoonTech's Sybil recognition model, after being deployed at a Southeast Asian client in 2025, identified and banned 4,200 Sybil account groups within 3 months, recovering approximately $1.2 million of potential loss.

6. Spoofing, Fake Liquidity, and Order Book Manipulation

6.1 Definition of Spoofing

Spoofing is market manipulation explicitly defined by the 2010 US Dodd-Frank Act: a trader places a large order with no intent to execute, in order to fake demand/supply, then cancels after other traders follow and trades in the opposite direction for profit.

In a prediction-market order book, a typical scenario:

  1. Attacker places a $500,000 buy order on Yes at 0.40, faking "strong buying";
  2. Retail sees the buying and follows, pushing Yes to 0.45;
  3. Attacker cancels and sells a pre-built Yes position at 0.45;
  4. Price returns to 0.41, attacker profits 5% × position.

6.2 Layering

Layering is an upgraded version of spoofing: the attacker places orders at multiple price levels to fake "depth" but does not intend any of them to be filled. For example:

  • Place three $100,000 buy orders at 0.40/0.41/0.42;
  • Place three $100,000 sell orders at 0.44/0.45/0.46;
  • Forms a "4bp spread, $300,000 depth" illusion in the middle;
  • After retail trades at mid, the attacker cancels one side and reverses.

6.3 Detection Features

FeatureMeaningThresholdorder_to_trade_ratio

Order size / fill size

> 20x

cancel_rate

Cancel count / total order count

> 80%

cancel_latency

Time from order placement to cancel

< 10s

price_distance_to_touch

Distance from order price to best price

> 2bp

cancel_after_other_trade

Whether cancel follows other people's fill on the same side

yes

inventory_imbalance

Account position direction after cancel

opposite to cancel direction

layer_count

Number of price levels on the same side

> 3

Order-to-trade ratio = order size / fill size. When it exceeds 20x, a medium alert is triggered; cancel rate over 80% and cancel latency < 10s is strong evidence of spoofing.

6.4 Real Liquidity vs. Fake Liquidity

Distinguishing real from fake liquidity is a common challenge for prediction-market market makers and regulators. SoonTech's approach introduces a "Liquidity Confidence Score":

  • Each level's liquidity is weighted by "volume in the last 1 hour / order size";
  • Long-lived orders rarely filled (ghost orders) are down-weighted;
  • During rapid price moves, an order side that does not follow the price = high confidence (MM), that follows or cancels = low confidence (possible spoofing);

This score is exposed to the frontend (color scale or icon), so users can intuitively see "which liquidity is real".

6.5 Marking the Close

The "close price" of a prediction market corresponds to the implied price or last fill at settlement. An attacker may concentrate buying in the last 5–10 minutes before settlement, pushing the close close to 1.00, triggering cascade effects in other systems: automatic settlement, index-fund NAV pricing, market-maker reconciliation.

Detection points:

  • Abnormal volume spike in the last N minutes (N typically 5–15 min);
  • Concentrated single-direction position in accounts before settlement, especially newly registered or long-dormant;
  • Synchronized operation by multiple accounts under the same controller.

SoonTech recommends entering "high-pressure mode" 30 minutes before settlement: all new orders are capped at 0.5x limit, abnormal accounts have new positions frozen, and key events require manual confirmation.

7. Oracle and Settlement Source Manipulation Defense

7.1 The Severity of Oracle Attacks

The oracle is the "trust anchor" of a prediction market; once breached, all positions in the entire event chain can be settled incorrectly. In 2023, a major prediction platform once settled a cancelled match as "home team win" due to a data source error, causing $2.8M of incorrect payouts; in 2024, another platform settled a macro data event incorrectly because an aggregator returned a polluted API response.

7.2 Attack Surfaces

Attack SurfaceDescriptionDefenseData source API error

Provider API failure, returns wrong data

Multi-source aggregation, median check

API key leak

Oracle signing key stolen

Multi-sig, HSM, key rotation

Proposer bribery

Proposer accepts a bribe to submit wrong result

Large bond + challenge period

Challenger censorship

Malicious challenger blocks correct result

Increasing challenge cost, cooling-off

Timezone & timestamp manipulation

Data source timestamps attacked

At least 3 independent time sources

Subjective event ambiguity

Ambiguous description, attacker picks favorable interpretation

Strict market creation review

ZK proof forgery

Attacker forges a ZK proof

Multiple verifiers, trust-minimized circuit

7.3 Multi-Source Aggregation and Median

For quantifiable events (sports scores, crypto prices, macro data), SoonTech mandates at least 3 independent data sources:

  • At least two of Chainlink, API3, UMA, plus in-house data collection;
  • At least 2 sources must return consistent results to advance to the propose stage;
  • On disagreement, trigger "delayed settlement" or "manual review" workflow.

For subjective events (politics, entertainment), strict event description plus at least 3 independent verifiable sources are required; the proposer must attach links and original text when proposing.

7.4 Optimistic Oracle and Challenge Period

Drawing on UMA's Optimistic Oracle design:

  • Propose phase: proposer submits result + evidence links, stakes a bond;
  • Challenge phase (2–24h): anyone can challenge, challenger must stake a higher bond;
  • No-challenge auto-pass: if no challenge within the period, result takes effect automatically;
  • Escalation: dispute escalates to higher-level resolution (council, DAO vote, off-chain court).

The challenge period should be dynamically adjusted by event value—2h for low value, 24h for high value, 72h for political elections. SoonTech's implementation allows custom challenge period at market creation.

7.5 Data Signatures and Verifiable Evidence

Next-generation oracles require data sources to provide verifiable evidence:

  • API signatures: data source signs the response with an Ed25519 private key, oracle verifies the signature;
  • TLS Notary / DECO: prove the data really came from a specific HTTPS endpoint;
  • Official page snapshots: anchor the official page at a specific time with OpenTimestamps or IPA (Inheritance Proof of Authority);
  • News agency digital signatures: Reuters, AP sign official announcements.

SoonTech's Oracle Hub integrates Chainlink Functions, API3 QRNG, UMA Optimistic Oracle, and in-house verifiable evidence storage.

8. Layered Detection Architecture: Rules, Statistics, Graph Algorithms, and Machine Learning

8.1 Why Layers Are Needed

Any single detection method has limits:

  • Pure rules: high precision, but low recall, hard to detect "unseen" patterns;
  • Pure ML: high recall, but black-box, hard to explain, easy to bypass with adversarial samples;
  • Pure graph: strong on structured association, but weak on time-series and text signals;
  • Pure statistics: sensitive to anomalies, but thresholds hard to tune, high false positive rate.

In production, SoonTech uses a four-layer architecture, each with clear responsibility and independent upgrade:

LayerTechResponsibilityLatencyFalse Positive RateL1 Rules engine

Drools / in-house DSL

Known violations, hard compliance rules

< 10ms

very low

L2 Statistical anomaly

CUSUM / EWMA / Isolation Forest

Statistical anomalies of known patterns

100ms–1s

low

L3 Graph algorithms

Neo4j / TigerGraph / GraphX

Account linkage, closed loops, groups

1–10s

medium

L4 Machine learning

XGBoost / GNN / Transformer

Complex patterns, unseen threats

10s–minutes

medium-high

Each layer outputs "suspicion score + evidence", and an "alert aggregator" scores and pushes to the alert queue.

8.2 L1 Rules Engine

The rules engine is the compliance baseline, with three responsibilities:

  1. Hard compliance rules: geographic restrictions, age limits, KYC status, single-trade limits, cumulative limits;
  2. Known violation patterns: self-match detection, obvious spoofing patterns, known Sybil addresses;
  3. Regulatory report triggers: directly generate SAR/STR drafts when specific thresholds are hit (cumulative volume, single-trade size).

Rules are written in DSL (SoonTech's DSL is similar to WHEN account.age < 7d AND trade.size > 10000 THEN alert("new_account_large_trade")), supporting hot-reload, version control, and A/B testing.

8.3 L2 Statistical Anomaly

Maintain time series for each account and each market:

  • Volume, order size, cancel rate rolling mean and variance;
  • z-score and IQR of price changes;
  • CUSUM / Page-Hinkley cumulative deviation.

When an indicator deviates from historical distribution beyond a threshold (e.g., 3σ or 99.5 percentile), trigger an alert. This layer mainly detects "statistical anomalies of known patterns", e.g., "an account's volume in 1 hour is 10x the past 30 days".

8.4 L3 Graph Algorithms

Prediction markets have rich graph structures:

  • Account-account graph: edges through common device, IP, fund association;
  • Account-market graph: bipartite graph through trading behavior;
  • Fund-on-chain address graph: directed graph of deposit/withdraw;
  • Event-information source graph: time correlation between events and accessible sources.

We run three types of algorithms on Neo4j / TigerGraph:

  • Community detection (Louvain / Leiden): identify highly associated account groups;
  • Anomalous nodes (oddball / Ego-splitting): nodes with high degree but anomalous features;
  • Subgraph matching: search specific patterns (e.g., "5 accounts wash-trading synchronously on 3 markets").

The advantage of graph algorithms is "explainability"—each suspicious group can be visualized for the compliance officer.

8.5 L4 Machine Learning

ML detects complex, unseen patterns:

  • XGBoost / LightGBM: strong baseline on structured features, binary classification of "is the account suspicious";
  • GNN (Graph Neural Network): embedding of account-market-address graph, used for "are accounts collaborating";
  • Transformer / LSTM: trade sequence modeling, "is the behavior pattern abnormal";
  • Autoencoder / Isolation Forest: unsupervised anomaly detection for "new unknown patterns".

The model outputs probability + key feature contributions (SHAP values) for human review.

8.6 Alert Aggregation and Deduplication

The same abnormal behavior may be triggered by multiple layers simultaneously (e.g., rule, statistical, ML all hit), so aggregation and deduplication are needed:

  • Use event ID (account + market + time window) as dedup key;
  • Merge alerts of the same root cause within a 5-minute window;
  • Output "composite suspicion" and "main contributing layer", making human review intuitive.

9. Alert Tiering, Human Review, and Enforcement Actions

9.1 Alert Tiers

SoonTech uses four alert tiers, mapping to different SLAs and enforcement paths:

TierMeaningTrigger ExampleResponse SLAEnforcement AuthorityP0 Critical

Platform survival threat, regulatory red line

Large-scale Sybil attack, oracle breach

5 min

CEO + Compliance Director

P1 High

Clear manipulation evidence, freeze immediately

5+ accounts insider trading in sync

30 min

Compliance Director + Risk Manager

P2 Medium

Highly suspicious, manual review required

Account with self-match rate > 50%

4 hours

Risk Manager + On-call Compliance

P3 Low

Weak signal, batch processing

Volume deviating by 2σ

24 hours

On-call Compliance

9.2 Human Review Workflow

Human review is not "glance and pass"—it requires a standardized process:

  1. Receive alert: system pushes to compliance officer's ticket system with an evidence package (suspicious trades, association graph, model SHAP, account profile);
  2. Quickly classify: within 5 minutes decide "false positive", "keep watching", "escalate";
  3. Evidence freeze: archive account state, trade records, device fingerprint, on-chain addresses to evidence storage (write to read-only log + on-chain anchor);
  4. Decision and execution: choose enforcement action (see next section), submit dual-signature approval;
  5. Follow-up and archive: after enforcement, follow 7/30/90 days, confirm no recurrence, write into case library for model training.

Compliance officers work 24/7 in shifts, with at least 2 per shift to avoid single-point negligence. SoonTech's ticket system has a built-in "dual review" mechanism—any P0/P1 enforcement requires two independent approvals to execute.

9.3 Enforcement Actions

ActionApplicable SituationSide EffectLegal RiskWarning

First violation, minor

Almost none

Low

Feature restriction

Frequent violations, need to observe

User experience drops

Medium

Freeze account

Clear violation, need investigation

User complaints

Medium

Cancel order / trade

Self-match, obvious error

Market impact

Medium (require ToS disclosure)

Market void

Market manipulated, event invalid

Platform reputation

Medium (need clear rules)

Settlement delay

Dispute exists, review needed

User experience drops

Medium

Fund slash

Severe violation, protocol rule exists

User litigation

Medium (need ToS clarity)

Refer to judicial

Involves criminal offense, cross-border

Long litigation

High

The platform must clearly specify in ToS and market rules the trigger conditions, approval process, and appeal path for each action. This is not only a legal compliance requirement, but also "prior notice" to users.

9.4 Market Voiding

Market voiding is one of the most severe enforcement actions, usually used in:

  • Event description has unresolvable ambiguity;
  • Substantial evidence shows the result was manipulated;
  • Oracle breached and cannot be resolved within the challenge period;
  • Regulator explicitly requires.

Capital handling after voiding:

  • Equal-proportional redemption: all shares redeem at 1/N, manipulator and other users treated equally;
  • Compensation fund: use the "invalid-market insurance pool" to buy back non-violating users' positions at the last normal price;
  • Partial void: only void the manipulated sub-outcome, others settle normally.

SoonTech recommends that voiding decisions be jointly reviewed by compliance + legal + business, with decision rationale and evidence chain recorded.

10. Dispute Resolution, Evidence Chains, and Explainability

10.1 Three-Layer Dispute Architecture

Drawing on UMA's Optimistic Oracle and Augur's fork mechanism, SoonTech implements three layers of dispute resolution:

  1. Layer 1: Propose–Challenge (2–24h)
  • Proposer submits result + evidence, stakes a bond;
  • Anyone can challenge, challenger must stake a higher bond;
  • Auto-pass if no challenge.
  1. Layer 2: Council Vote (3–7 days)
  • On challenge, 9–15-person council votes (SoonTech clients can customize members);
  • Simple majority passes, proposer/challenger split bond by outcome;
  • Vote details on-chain, each member's reasoning can be public.
  1. Layer 3: DAO or Jurisdiction (7–30 days)
  • Extreme disputes (involving millions of dollars or constitutional questions) escalate to DAO vote or specific jurisdiction arbitration;
  • This is the "nuclear button", rarely triggered.

10.2 Evidence Chain Retention

Any enforcement action (order cancel, freeze, void) must have an auditable evidence chain:

  • Account state snapshot: KYC status, position, funds, risk score at the moment of action;
  • Trade details: complete trade history of involved accounts, counterparties, IPs, device fingerprints, timestamps;
  • Model output: suspicion score, key feature contributions (SHAP), related alerts;
  • Decision record: decision maker, decision time, decision rationale, reviewer;
  • Follow-up: account behavior changes at 7/30/90 days.

SoonTech's compliance system writes the evidence package into read-only logs (PostgreSQL + S3) + on-chain anchoring (hourly log hash written to Ethereum/Polygon), ensuring immutability and long-term queryability.

10.3 Explainability

Regulators and courts increasingly require AI decisions to be explainable. SoonTech's practice:

  • Rule alerts: each rule has a natural-language description ("account associated with 3 IPs in 24 hours");
  • Statistical alerts: show time series chart, threshold line, statistical value;
  • ML alerts: attach SHAP feature contribution chart, marking "why this account was flagged";
  • Graph alerts: visualize association graph, marking "why these accounts are linked".

Compliance officers can use natural language to explain to regulators or users: "This account was flagged because it used the same Wi-Fi BSSID as 4 known Sybil accounts within 30 minutes before the event, and funded from the on-chain address 0xab12..."

11. Regulatory Reporting and Compliance Integration

11.1 Major Southeast Asian Jurisdictions

JurisdictionRegulatorRegulatory FocusReporting RequirementsMalaysia

SC Securities Commission Malaysia

Capital market manipulation, insider trading, KYC/AML

Quarterly trade reports, immediate STR

Indonesia

BAPPEBTI (futures) / OJK (securities)

Futures trading surveillance, AML

Real-time surveillance, monthly compliance reports

Thailand

SEC Thailand

Digital assets, AML

Real-time anomaly reports, annual compliance audit

Singapore

MAS (Monetary Authority of Singapore)

DPT (Digital Payment Token), AML/CFT

Real-time STR/CTR, annual compliance reports

Vietnam

Central Bank + Ministry of Information and Communications

Digital assets, AML

Pilot period, gradual integration required

Philippines

BSP (Central Bank) + SEC

Digital assets, AML

Quarterly reports + real-time STR

11.2 Report Content

Report TypeTrigger ConditionContentFrequencySuspicious Transaction Report (STR/SAR)

Hits AML rules

Account, trade, counterparty, evidence

Immediate

Currency Transaction Report (CTR)

Single or cumulative over threshold

Trade details, counterparty, KYC

Daily/weekly

Market manipulation report

Hits manipulation rules

Manipulation technique, accounts involved, loss estimate

Immediate + monthly

System security incident

Hacking, oracle failure

Event timeline, impact scope, remediation progress

Immediate

Annual compliance report

Yearly

Overall risk status, key events, improvement plan

Annual

Regulatory inquiry response

Regulator actively requests

Detailed data on specific accounts/markets

On-demand

11.3 Cross-Border Regulatory Coordination

Prediction markets are naturally cross-border—users may deposit in the Philippines, trade in Malaysia, withdraw in Indonesia. SoonTech's compliance system supports:

  • Cross-jurisdiction compliance rule library (each rule can specify applicable region);
  • Automatic reporting of cross-border suspicious transactions (Philippines account + Malaysia market + Indonesia withdrawal → simultaneously report to three regulators);
  • API integration with regulators (MAS, SC, SEC Thailand all have dedicated API specifications);
  • Regulatory sandbox mode (anonymize or restrict specific features as required).

12. Engineering Architecture and Performance Design

12.1 Overall Architecture

The full surveillance pipeline runs from the trading entry point all the way to human enforcement, and decomposes into seven layers along the data flow:

  1. Entry layer: Client and mobile requests pass through the API Gateway into the matching engine or AMM. The gateway simultaneously captures identity-side raw signals such as device fingerprint, IP, and user agent.
  2. Event bus: The matching engine writes every fill, order placement/cancellation, and position change into Kafka topics such as trade-event-stream and order-event-stream, serving as the single source of truth for all downstream detection modules.
  3. Real-time compute layer: Flink jobs consume the event streams and aggregate real-time features by account, market, and time window—self-match ratio, order-to-cancel ratio, settlement-window volume share, and so on.
  4. Feature store layer: Real-time features are written to Redis or a feature store for low-latency online inference, with a parallel copy landed in the data lake for offline training and backtesting.
  5. Inference and aggregation layer: Rule engine, statistical models, and machine learning models score in parallel; the alert aggregation service deduplicates, merges same-origin signals, and computes a final risk score.
  6. Graph analytics layer: A graph database such as Neo4j carries the account–device–funding–on-chain-address linkage network. Offline jobs periodically recompute community detection and linkage strength, feeding results back as account-level features.
  7. Enforcement layer: Alerts crossing threshold enter the alert queue and ticketing system, routed by severity to on-call risk staff, compliance review, or automated enforcement actions.

12.2 Stream Processing Core: Flink + Kafka

  • Kafka carries all trade events, user behavior, on-chain events, oracle events;
  • Flink is responsible for real-time feature computation (sliding windows, CEP complex event processing), real-time model inference, real-time alert generation;
  • Flink CEP is especially suited to detect "time-series patterns" (e.g., "A places 3 orders in 5 minutes, 30 seconds apart");
  • Exactly-Once semantics ensures alerts are not duplicated or missed (key compliance requirement).

12.3 Feature Store

SoonTech recommends a tiered feature store:

  • Real-time features (Redis / Aerospike): < 1ms latency, for Flink real-time compute;
  • Offline features (Parquet on S3 / Hudi): T+1, for offline model training;
  • Feature platform (Feast / Tecton): unified feature definition, versioning, cross-team sharing;
  • Online inference (< 100ms) and offline training share the same feature definition, avoiding training-serving skew.

12.4 Graph Database

  • Neo4j for small-to-medium scale (< 100M nodes) association analysis;
  • TigerGraph for large-scale (billion-level nodes) graph algorithms;
  • GraphX / NetworkX for one-time offline analysis (community detection, subgraph matching);
  • Amazon Neptune / Alibaba GraphScope for cloud-native deployment.

Common graph queries:

  • "Accounts sharing C-segment IP with known Sybil accounts in the last 24h";
  • "On-chain deposit addresses of account X in the last 7 days, graph after Common Spending clustering";
  • "Shortest time window in which 5 accounts wash-traded synchronously on 3 markets".

12.5 Performance and Availability

MetricTargetDesignAlert latency (P95)

< 1s

Flink streaming + real-time features

Model inference latency (P99)

< 100ms

Online inference + model cache

Graph query latency

< 5s

Pre-compute + index + subgraph cache

System availability

99.95%

Multi-active deployment, circuit breaker, degradation

Throughput

100K TPS trade events

Kafka partitions + Flink parallelism

Storage

5-year compliance retention

Hot/cold tiered + object storage

13. SoonTech Market Surveillance Solution

13.1 Solution Overview

SoonTech's Market Surveillance suite is a key piece of infrastructure for prediction-market platforms, sitting alongside AMM, order book, and oracle. Module composition:

  1. Data ingestion layer: trade events, user behavior, on-chain events, oracle events, device fingerprints;
  2. Real-time processing layer: Kafka + Flink real-time features and CEP;
  3. Detection layer: rules engine (L1) + statistical anomaly (L2) + graph algorithms (L3) + machine learning (L4);
  4. Alert and ticket: tiered alert, dual review, evidence chain;
  5. Enforcement and execution: position limit, order cancel, freeze, void, settlement delay;
  6. Compliance report: STR/CTR, regulator API integration, cross-border coordination;
  7. Explainability and audit: SHAP, evidence chain, on-chain anchoring;
  8. Admin console: compliance officer workbench, case library, model monitoring, rule management.

13.2 Three Typical Deployment Scenarios

Scenario 1: Prediction Markets Embedded in a Top Southeast Asian CEX

The client is a licensed CEX in Singapore/Malaysia that wants to add a prediction-market business to its existing App while satisfying MAS and SC compliance requirements. We deploy the full surveillance suite, customize the rule library per MAS DPT and SC Guidelines, and align the alert tiering and enforcement flow with the client's existing compliance department. Within 6 months of launch, we identified and handled 380 suspicious transactions, recovered $2.2M of potential loss, and had zero major findings in regulatory inspections.

Scenario 2: Indonesia Standalone UGC Prediction Market

The client is a UGC prediction market targeting Indonesian users, covering sports, esports, and politics. We strengthened Sybil identification (Indonesian account farms are active), social graph analysis (prediction influencers on Twitter/Instagram), and incentive arbitrage detection (airdrop/leaderboard farming). Within 4 months of launch, 1,800+ Sybil account groups were banned, and farming-related complaints dropped 92%.

Scenario 3: Global Decentralized Prediction Market

The client is a decentralized prediction market deployed on Polygon/Base, emphasizing "no KYC required, fully on-chain." Under a privacy-preserving premise (using ZK proofs + on-chain behavior), we perform Sybil identification, oracle attack detection, and cross-protocol fund tracking. After launch, we partnered with multiple MEV protection services and on-chain analytics providers to build a "light KYC, strong on-chain analytics" hybrid surveillance system.

13.3 Delivery Cadence

  • Weeks 1–2: business research, regulatory requirements, initial rule library;
  • Weeks 3–6: data ingestion and Kafka integration, Flink real-time features, rules engine;
  • Weeks 7–8: graph database and offline features, ML model training;
  • Weeks 9–10: ticket system, compliance department integration, drill;
  • Week 11: live trial, gray-scale rules;
  • From week 12: tune thresholds based on alert quality, expand rules and models.

14. Enterprise Implementation Recommendations

14.1 Three Phases of Surveillance Construction

Phase 1 (Survival): Rules + Statistics (0–3 months)

  • Kafka/Flink integration, rules engine, self-match/spoofing/limit rules;
  • Focus on minimum regulatory requirements (KYC/AML/STR);
  • A team of 2–3 can run it.

Phase 2 (Defense): Graph + ML (3–9 months)

  • Build graph database, address clustering, behavior similarity;
  • Deploy XGBoost/GNN models;
  • Team grows to 5–8, including data scientists.

Phase 3 (Leading): Predictive + Proactive (9–18 months)

  • Use Agentic AI for Compliance for proactive hunting;
  • Build information-sharing mechanisms with regulators;
  • Form an industry-leading compliance brand.

14.2 Team Composition

Minimum surveillance team:

  • 1 Compliance Lead (regulator interface, policy);
  • 2 Compliance Officers (7×24 shifts, alert review and enforcement);
  • 2 Data Engineers (Kafka/Flink/graph database);
  • 1 Data Scientist (ML model training and tuning);
  • 1 Risk Product Manager (rule library iteration, case management);
  • 1 Legal (cross-border compliance, dispute resolution).

With SoonTech's outsourcing and consulting services, a complete surveillance system can be built in 3 months.

14.3 Key Metrics

  • Alert quality: P0/P1 false positive rate < 5%, P2/P3 < 20%;
  • Alert latency: P0 < 5 min, P1 < 30 min, P2 < 4 hours;
  • Enforcement closure: 100% of alerts handled within SLA, 100% of enforcements have complete evidence chain;
  • Model metrics: Sybil identification recall > 85%, insider trading recall > 70%;
  • Regulatory compliance: 0 missed STR/CTR, regulator inquiry response < 24 hours;
  • Business impact: false-freeze rate < 0.1%, user complaint rate < 0.05%.

14.4 Common Pitfalls

  • Over-reliance on ML: many teams start by trying to "use AI to solve everything", only to get 5% recall and 80% false positive. We recommend starting with rules + statistics; use ML only where rules can't cover;
  • Alert fatigue: too many alerts desensitize compliance officers, who then miss the real P0. Must strictly tier, allocate, and merge;
  • Missing evidence chain: only when you want to pursue liability after the fact do you realize evidence was not stored. Evidence chain must be considered on day one of system design;
  • Lack of regulator communication: only explaining when regulators come to check. Proactively establish communication channels with regulators and report periodically;
  • Cross-border compliance vacuum: thinking "where the user is, the rule follows", but in fact the platform's registered place, server location, and the user's physical location all involve different compliance requirements.

FAQ

Q1: Why are prediction markets easier to manipulate than spot exchanges?

A: Three root causes: 1) settlement is binary, so manipulation gains scale non-linearly (0.30→0.90 = 200% return); 2) 95% of events have daily volume below $50K, a single order can set the price; 3) information asymmetry is natural (a player's family, a politician's aide can build a position in the minutes before public information). These three features combined make prediction markets a hotspot for insider trading, wash trading, Sybil attacks, and settlement-window sniping.

Q2: How do you distinguish insider trading from "doing homework"?

A: It's hard to 100% distinguish, but you can judge by several signals: 1) gap between position-building time and information-source public time (< 30 min is highly suspicious); 2) account-group clustering (multiple accounts building position in the same direction at the same time); 3) account characteristics (newly registered, first appearing cross-platform, IP/device associated with known violators); 4) whether the information source is "non-public" (starting lineup, internal vote, unreleased economic data are all "non-public information"). SoonTech's insider-detection model scores on 8 features; a score > 0.65 triggers a high-tier alert.

Q3: How high is the self-match rate to be considered severe?

A: SoonTech recommends three thresholds: self-match rate = counterparty volume from affiliated accounts / total volume of the account. > 30% triggers a medium alert, > 50% a high alert, > 70% immediate freeze and manual review. Pure "self-match" isn't necessarily wash trading (professional market-maker hedging can also produce affiliated-account trades), but it must be judged in combination with closed-loop PnL, cancel rate, and account-association strength.

Q4: Won't Sybil detection harm "family members sharing a device"?

A: Yes, this is the biggest challenge for Sybil detection. SoonTech's approach: 1) whitelist "family scenarios" (same Wi-Fi BSSID + same shipping address + associated KYC ID); 2) but if multiple accounts trade a lot from the same device and in highly aligned directions, still treat as abnormal ("family users" rarely precisely synchronized trade); 3) strengthen KYC (face recognition, ID four-element) to reduce account farms at the source; 4) periodically manually review flagged groups to distinguish "family users" from "account farms".

Q5: After a market is manipulated, is Void the best enforcement?

A: Not necessarily. Void is the most severe enforcement, hurting platform reputation and all user trust, and should be the last resort. SoonTech's recommended priority: 1) freeze involved accounts + cancel orders (smallest impact); 2) settlement delay (time for investigation); 3) partial void (only void the manipulated sub-outcome); 4) full market void + insurance pool compensation (extreme). Void should be jointly reviewed by compliance + legal + business, and clearly explained externally.

Q6: How can regulatory reporting be both compliant and efficient?

A: SoonTech's compliance system makes regulatory reporting "configuration-driven": each report rule configures trigger conditions, content templates, submission method, regulator, and frequency. The system automatically extracts fields from surveillance alerts and trade data, generates report drafts, and after compliance officer review, submits via API or manually. Meanwhile, we maintain a "regulator inquiry response library" that turns common regulator questions into templates, compressing average response time from 5 days to 1 day.

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