getOutcomeProbabilityAfterBet

common/calculate-cpmm.ts

@@ -8,13 +8,14 @@ export function getCpmmProbability(pool: { [outcome: string]: number }) {
   return NO / (YES + NO)
 }
 
-export function getCpmmProbabilityAfterBet(
+export function getCpmmOutcomeProbabilityAfterBet(
   contract: FullContract<CPMM, Binary>,
   outcome: string,
   bet: number
 ) {
   const { newPool } = calculateCpmmPurchase(contract, bet, outcome)
-  return getCpmmProbability(newPool)
+  const p = getCpmmProbability(newPool)
+  return outcome === 'NO' ? 1 - p : p
 }
 
 export function calculateCpmmShares(

common/calculate-dpm.ts

@@ -19,7 +19,7 @@ export function getDpmOutcomeProbability(
   return shares ** 2 / squareSum
 }
 
-export function getDpmProbabilityAfterBet(
+export function getDpmOutcomeProbabilityAfterBet(
   totalShares: {
     [outcome: string]: number
   },

common/calculate.ts

@@ -3,7 +3,7 @@ import {
   calculateCpmmShares,
   calculateCpmmShareValue,
   getCpmmProbability,
-  getCpmmProbabilityAfterBet,
+  getCpmmOutcomeProbabilityAfterBet,
   getCpmmProbabilityAfterSale,
 } from './calculate-cpmm'
 import {
@@ -13,7 +13,7 @@ import {
   calculateDpmShares,
   getDpmOutcomeProbability,
   getDpmProbability,
-  getDpmProbabilityAfterBet,
+  getDpmOutcomeProbabilityAfterBet,
   getDpmProbabilityAfterSale,
 } from './calculate-dpm'
 import {
@@ -42,18 +42,18 @@ export function getOutcomeProbability(contract: Contract, outcome: string) {
     : getDpmOutcomeProbability(contract.totalShares, outcome)
 }
 
-export function getProbabilityAfterBet(
+export function getOutcomeProbabilityAfterBet(
   contract: Contract,
   outcome: string,
   bet: number
 ) {
   return contract.mechanism === 'cpmm-1'
-    ? getCpmmProbabilityAfterBet(
+    ? getCpmmOutcomeProbabilityAfterBet(
         contract as FullContract<CPMM, Binary>,
         outcome,
         bet
       )
-    : getDpmProbabilityAfterBet(contract.totalShares, outcome, bet)
+    : getDpmOutcomeProbabilityAfterBet(contract.totalShares, outcome, bet)
 }
 
 export function calculateShares(

web/components/bet-panel.tsx

@@ -23,7 +23,7 @@ import {
   calculatePayoutAfterCorrectBet,
   calculateShares,
   getProbability,
-  getProbabilityAfterBet,
+  getOutcomeProbabilityAfterBet,
 } from '../../common/calculate'
 import { useFocus } from '../hooks/use-focus'
 
@@ -99,7 +99,7 @@ export function BetPanel(props: {
 
   const initialProb = getProbability(contract)
 
-  const outcomeProb = getProbabilityAfterBet(
+  const outcomeProb = getOutcomeProbabilityAfterBet(
     contract,
     betChoice || 'YES',
     betAmount ?? 0