Polymarket Mispricing Events

Detects mispricings on Polymarket by cross-referencing Kalshi and Manifold consensus probability, then trades the gap using Kelly criterion sizing. Enters wh...

Security Scan

The skill's code, declared dependencies, and runtime instructions are coherent with its stated purpose (cross‑platform arbitrage using a Simmer trading client); it requests the expected trading API key and uses public market APIs, with no obvious unrelated privileges or secret exfiltration.

Purpose & Capability

The skill claims to detect and trade Polymarket mispricings and does so: it fetches Polymarket/Kalshi/Manifold data and uses SimmerClient to submit trades. The only required secret is SIMMER_API_KEY, which is appropriate for a trading bot.

Instruction Scope

SKILL.md and the code limit activity to fetching public market APIs, fuzzy matching titles, computing consensus, and placing trades via SimmerClient. One small inconsistency: the code reads EVENTS_MISPRICING_MIN (ENV var) but that variable is not listed in the SKILL.md env table—otherwise instructions stay within the stated trading scope and do not read unrelated system files or secrets.

Install Mechanism

This is instruction‑only but clawhub.json requests pip packages (simmer-sdk, requests, urllib3). Installing pip packages is expected for this skill; review the simmer-sdk package provenance before granting API keys. No arbitrary URL downloads or archive extraction are present.

Credentials

Only SIMMER_API_KEY (and optional EVENTS_* configuration envs) are required. That is proportional: the skill needs a trading API key to submit orders. Remember this key grants trading capability and should be treated as highly sensitive.

Persistence & Privilege

The skill is not marked always:true and is user‑invocable; it may run autonomously per platform defaults. Because it can place trades, allow autonomous invocation only if you trust the code and the Simmer account permissions; otherwise run in 'sim' (paper) mode first.

Assessment

This skill appears to do what it says: scanning public markets and placing trades through the Simmer SDK. Before installing, do the following: 1) Verify the simmer-sdk package is the official client and review its docs/source so you know what API scope the key allows. 2) Start with TRADING_VENUE=sim (paper) to confirm behavior and avoid real money loss. 3) Provide SIMMER_API_KEY only to an account with limited funds/permissions and rotate the key after testing. 4) Note the small doc/code mismatch: EVENTS_MISPRICING_MIN is used in code but not documented in SKILL.md—check intended behavior. 5) Audit network egress if you require strict controls (the skill calls Polymarket, Kalshi, Manifold, and Simmer endpoints). If you need higher assurance, request the full, non‑truncated source and a dependency manifest to review the Simmer SDK and third‑party packages.

Detects and trades mispricings on Polymarket by comparing market prices against a consensus probability estimated from Kalshi and Manifold using fuzzy title matching.

Strategy

1. Fetches all active Polymarket binary markets (top 500 by liquidity)
2. For each market, searches Kalshi and Manifold for the same event via Jaccard title similarity
3. Computes weighted consensus probability (Kalshi 55%, Manifold 45%)
4. Enters if gap between consensus and Polymarket price exceeds threshold (default 15%)
5. Sizes position with quarter-Kelly criterion, capped between $5 and $50
6. Skips markets with flip-flop warnings, high slippage, or insufficient edge

Edge

Cross-platform prediction market arbitrage. When two independent markets disagree by 15%+ on the same event, one of them is wrong. This skill bets on the consensus.

When it works best

• Political, macro, and sports markets with active Kalshi/Manifold counterparts
• Events with clear resolution criteria
• Markets in the 15%-85% probability range (not near-resolved)

Configuration (env vars)

Variable	Default	Description
SIMMER_API_KEY	required	Your Simmer API key
TRADING_VENUE	sim	sim for paper, live for real money
EVENTS_ENTRY_THRESHOLD	0.15	Minimum gap to enter (15%)
EVENTS_KELLY_FRACTION	0.25	Kelly multiplier (0.25 = quarter-kelly)
EVENTS_TRADE_SIZE_MIN	5.0	Minimum trade size in USD
EVENTS_TRADE_SIZE_MAX	50.0	Maximum trade size in USD
EVENTS_MAX_POSITIONS	8	Maximum open positions
EVENTS_MIN_LIQUIDITY	500.0	Minimum market liquidity
EVENTS_MAX_GAP_CAP	0.35	Reject gaps > 35% (model likely wrong)

Risk

• Cross-platform matching via fuzzy text can produce false positives — keep position sizes conservative
• Rare markets may have no Kalshi/Manifold counterpart — these are skipped
• Kelly sizing still carries variance risk; recommend starting with sim venue