{"uid":"cap_ZmcLbv5QxGFy8BA_AWAGJ","slug":"binary-outcome-ev-no-side-calculator-1ce52f51","name":"Binary Outcome EV (No Side) Calculator","description":"Expected value of buying binary NO at (1−yes_price) under true_prob. Call when checking the NO side when YES is mispriced the other way. Returns EV per $1 notional on NO 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/binary-ev-no","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"stake":{"type":"integer","description":"Input field: stake."},"true_prob":{"type":"number","description":"Input field: true prob."},"market_price":{"type":"number","description":"Input field: market price."}}},"responseSchema":{"type":"json","example":{"ev":-13.46153846153848,"stake":100,"schema":"delx/util-binary-ev-no/v1","shares":192.3076923076923,"no_price":0.52}},"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_gIdmbRJjSz_KQw9OR_GRn","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 value of a 'No' position in a binary prediction market given stake, true probability, and current market price.","exampleAgentPrompt":"What's the expected value of a No position if I stake 100 units, I think the true probability is 35%, and the current No price is 0.52?","exampleUseCases":[{"title":"Pre-trade EV check on prediction market","prompt":"I'm looking at a binary prediction market where I think the true probability of the event is 30%, the No price is 0.55, and I want to stake 200 units — what's the expected value of taking the No side?"},{"title":"Evaluating edge before scalping No contracts","prompt":"Before I place a No bet of 500 units on this market, can you calculate my EV? My true probability estimate is 40% and the current market no_price is 0.48."},{"title":"Sanity-checking a small No position","prompt":"I want to put 50 units on the No side of a binary market where I believe the true odds are 25% and the market is pricing No at 0.60 — is there positive EV here and how many shares would I get?"}],"resultDescription":"Returns a JSON object containing the computed expected value (ev, which can be negative), the stake echoed back, the number of No shares purchased, the effective no_price, and a schema identifier string (delx/util-binary-ev-no/v1).","failureModes":["Missing required fields (stake, true_prob, market_price) return a 400 validation error","Probability values outside [0,1] range may return an error or nonsensical EV","market_price of 0 or 1 causes division issues or degenerate results","Non-integer stake may be rejected or silently coerced","Payment failure or insufficient USDC balance returns a 402 error"],"whenToPreferThis":"Use this endpoint when you need a fast, cheap ($0.001 USDC) server-side computation of the expected value for the No side of a binary prediction market position. Prefer it over local calculation when you want a canonical, versioned result with a schema identifier for logging or auditing, or when the computation needs to be part of an x402-powered agent workflow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T07:14:48.912Z","isFirstParty":false}