{"uid":"cap_hmA_-wjfoozoNcSLUVWA3","slug":"delx-expected-log-growth-28baf8c7","name":"Delx Expected Log Growth","description":"Approx expected log bankroll growth for a binary bet fraction. Call when comparing bet sizes by growth rate under true_prob (advisory). Returns expected log growth as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.","url":"https://api.delx.ai/api/v1/x402/expected-log-growth","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"fraction":{"type":"number","description":"Input field: fraction."},"true_prob":{"type":"number","description":"Input field: true prob."},"market_price":{"type":"number","description":"Input field: market price."}}},"responseSchema":{"type":"json","example":{"schema":"delx/util-expected-log-growth/v1","fraction":0.1,"expected_log_growth":0.02704230164346613}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_WU9rlUSlFWyCJDcbe6rk-","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the expected logarithmic growth (Kelly criterion growth rate) given a bet fraction, true probability, and market price","exampleAgentPrompt":"What's the expected log growth if I bet a fraction of 0.1 with a true probability of 0.6 and a market price of 0.55?","exampleUseCases":[{"title":"Prediction market Kelly sizing check","prompt":"I'm about to stake a 15% fraction on a prediction market where I think the true probability is 65% but the market is pricing it at 58% — what expected log growth should I get from that position?"},{"title":"Portfolio bet growth optimization","prompt":"Can you calculate the expected log growth for a 20% fraction bet where my estimated true probability is 0.72 and the current market price is 0.68? I want to see if the edge is worth it."},{"title":"Comparing fractional bet sizes","prompt":"Run the expected log growth calculation for me: fraction 0.05, true probability 0.55, market price 0.52 — I want to know if this small edge at low stake is still positive."}],"resultDescription":"Returns a JSON object conforming to schema 'delx/util-expected-log-growth/v1', containing the input fraction and the computed expected_log_growth value (a float representing the expected logarithmic portfolio growth from taking that bet at the given fraction, true probability, and market price).","failureModes":["Missing required fields (fraction, true_prob, or market_price) return a validation error","Probabilities outside [0,1] or fractions outside valid range may produce undefined or error responses","Market price of 0 or 1 may cause division errors or infinite log values","Negative fraction values may return nonsensical results or errors"],"whenToPreferThis":"Use this endpoint when you need to compute the Kelly-criterion-style expected log growth for a binary bet or prediction market position given a specific fraction, true probability estimate, and market price. Prefer this over manual calculation when operating in an agent pipeline that needs a fast, governed, API-accessible computation of log-utility growth. Ideal for position-sizing workflows, portfolio optimization agents, or prediction market arbitrage bots that need to evaluate the value of an edge before committing capital.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:19:45.942Z","isFirstParty":false}