Sell bets (#12)

* sell bet

* dev mode

* single-pot no-refund payoff; bet selling

* Increase default fetch size 25 -> 99

* Fix about page numbering

* Don't flash no markets when loading on tag page.

* Change Title to use body font

* Make a bunch of predictions at once (#9)

* Set up a page to make bulk predictions

* Integrate preview into the same card

* List created predictions

* Make changes per James's comments

* Increase the starting balance (#11)

* Remove references to paying for our Mantic Dollars

* Update simulator to use new calculations

* Change simulator random to be evenly random again

* Sell bet UI

* Migrate contracts and bets script

* Add comment to script

* bets => trades; exclude sold bets

* change sale formula

* Change current value to uncapped sell value.

* Disable sell button while selling

* Update some 'bet' to 'trade'

Co-authored-by: Austin Chen <akrolsmir@gmail.com>
Co-authored-by: jahooma <jahooma@gmail.com>
This commit is contained in:
mantikoros 2021-12-24 15:06:01 -06:00 committed by GitHub
parent 856a2453a1
commit f48ae0170b
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
27 changed files with 589 additions and 204 deletions

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@ -1,5 +1,7 @@
{
"projects": {
"default": "mantic-markets"
"default": "mantic-markets",
"prod": "mantic-markets",
"dev": "dev-mantic-markets"
}
}

View File

@ -2,6 +2,7 @@
"name": "functions",
"scripts": {
"build": "tsc",
"watch": "tsc -w",
"serve": "yarn build && firebase emulators:start --only functions",
"shell": "yarn build && firebase functions:shell",
"start": "yarn shell",

View File

@ -2,6 +2,7 @@ import * as admin from 'firebase-admin'
admin.initializeApp()
export * from './keep-awake'
// export * from './keep-awake'
export * from './place-bet'
export * from './resolve-market'
export * from './sell-bet'

View File

@ -43,7 +43,7 @@ export const placeBet = functions.runWith({ minInstances: 1 }).https.onCall(
.collection(`contracts/${contractId}/bets`)
.doc()
const { newBet, newPool, newDpmWeights, newBalance } = getNewBetInfo(
const { newBet, newPool, newTotalShares, newBalance } = getNewBetInfo(
user,
outcome,
amount,
@ -54,7 +54,7 @@ export const placeBet = functions.runWith({ minInstances: 1 }).https.onCall(
transaction.create(newBetDoc, newBet)
transaction.update(contractDoc, {
pool: newPool,
dpmWeights: newDpmWeights,
totalShares: newTotalShares,
})
transaction.update(userDoc, { balance: newBalance })
@ -79,29 +79,19 @@ const getNewBetInfo = (
? { YES: yesPool + amount, NO: noPool }
: { YES: yesPool, NO: noPool + amount }
const dpmWeight =
const shares =
outcome === 'YES'
? (amount * noPool ** 2) / (yesPool ** 2 + amount * yesPool)
: (amount * yesPool ** 2) / (noPool ** 2 + amount * noPool)
? amount + (amount * noPool ** 2) / (yesPool ** 2 + amount * yesPool)
: amount + (amount * yesPool ** 2) / (noPool ** 2 + amount * noPool)
const { YES: yesWeight, NO: noWeight } = contract.dpmWeights || {
YES: 0,
NO: 0,
} // only nesc for old contracts
const { YES: yesShares, NO: noShares } = contract.totalShares
const newDpmWeights =
const newTotalShares =
outcome === 'YES'
? { YES: yesWeight + dpmWeight, NO: noWeight }
: { YES: yesWeight, NO: noWeight + dpmWeight }
? { YES: yesShares + shares, NO: noShares }
: { YES: yesShares, NO: noShares + shares }
const probBefore = yesPool ** 2 / (yesPool ** 2 + noPool ** 2)
const probAverage =
(amount +
noPool * Math.atan(yesPool / noPool) -
noPool * Math.atan((amount + yesPool) / noPool)) /
amount
const probAfter = newPool.YES ** 2 / (newPool.YES ** 2 + newPool.NO ** 2)
const newBet: Bet = {
@ -109,15 +99,14 @@ const getNewBetInfo = (
userId: user.id,
contractId: contract.id,
amount,
dpmWeight,
shares,
outcome,
probBefore,
probAverage,
probAfter,
createdTime: Date.now(),
}
const newBalance = user.balance - amount
return { newBet, newPool, newDpmWeights, newBalance }
return { newBet, newPool, newTotalShares, newBalance }
}

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@ -78,22 +78,27 @@ export const resolveMarket = functions
const firestore = admin.firestore()
const getPayouts = (outcome: string, contract: Contract, bets: Bet[]) => {
const [yesBets, noBets] = _.partition(bets, (bet) => bet.outcome === 'YES')
const openBets = bets.filter((b) => !b.isSold && !b.sale)
const [yesBets, noBets] = _.partition(
openBets,
(bet) => bet.outcome === 'YES'
)
const [pool, winningBets] =
const startPool = contract.startPool.YES + contract.startPool.NO
const truePool = contract.pool.YES + contract.pool.NO - startPool
const [totalShares, winningBets] =
outcome === 'YES'
? [contract.pool.NO - contract.startPool.NO, yesBets]
: [contract.pool.YES - contract.startPool.YES, noBets]
? [contract.totalShares.YES, yesBets]
: [contract.totalShares.NO, noBets]
const finalPool = (1 - PLATFORM_FEE - CREATOR_FEE) * pool
const creatorPayout = CREATOR_FEE * pool
const finalPool = (1 - PLATFORM_FEE - CREATOR_FEE) * truePool
const creatorPayout = CREATOR_FEE * truePool
console.log('final pool:', finalPool, 'creator fee:', creatorPayout)
const sumWeights = _.sumBy(winningBets, (bet) => bet.dpmWeight)
const winnerPayouts = winningBets.map((bet) => ({
userId: bet.userId,
payout: bet.amount + (bet.dpmWeight / sumWeights) * finalPool,
payout: (bet.shares / totalShares) * finalPool,
}))
return winnerPayouts.concat([

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@ -0,0 +1,58 @@
import * as admin from 'firebase-admin'
import * as _ from 'lodash'
import { Bet } from '../types/bet'
import { Contract } from '../types/contract'
type DocRef = admin.firestore.DocumentReference
// Generate your own private key, and set the path below:
// https://console.firebase.google.com/u/0/project/mantic-markets/settings/serviceaccounts/adminsdk
const serviceAccount = require('../../../../Downloads/mantic-markets-firebase-adminsdk-1ep46-820891bb87.json')
admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
})
const firestore = admin.firestore()
async function migrateBet(contractRef: DocRef, bet: Bet) {
const { dpmWeight, amount, id } = bet as Bet & { dpmWeight: number }
const shares = dpmWeight + amount
await contractRef.collection('bets').doc(id).update({ shares })
}
async function migrateContract(contractRef: DocRef, contract: Contract) {
const bets = await contractRef
.collection('bets')
.get()
.then((snap) => snap.docs.map((bet) => bet.data() as Bet))
const totalShares = {
YES: _.sumBy(bets, (bet) => (bet.outcome === 'YES' ? bet.shares : 0)),
NO: _.sumBy(bets, (bet) => (bet.outcome === 'NO' ? bet.shares : 0)),
}
await contractRef.update({ totalShares })
}
async function migrateContracts() {
console.log('Migrating contracts')
const snapshot = await firestore.collection('contracts').get()
const contracts = snapshot.docs.map((doc) => doc.data() as Contract)
console.log('Loaded contracts', contracts.length)
for (const contract of contracts) {
const contractRef = firestore.doc(`contracts/${contract.id}`)
const betsSnapshot = await contractRef.collection('bets').get()
const bets = betsSnapshot.docs.map((bet) => bet.data() as Bet)
console.log('contract', contract.question, 'bets', bets.length)
for (const bet of bets) await migrateBet(contractRef, bet)
await migrateContract(contractRef, contract)
}
}
if (require.main === module) migrateContracts().then(() => process.exit())

162
functions/src/sell-bet.ts Normal file
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@ -0,0 +1,162 @@
import * as admin from 'firebase-admin'
import * as functions from 'firebase-functions'
import { CREATOR_FEE, PLATFORM_FEE } from './resolve-market'
import { Bet } from './types/bet'
import { Contract } from './types/contract'
import { User } from './types/user'
export const sellBet = functions.runWith({ minInstances: 1 }).https.onCall(
async (
data: {
contractId: string
betId: string
},
context
) => {
const userId = context?.auth?.uid
if (!userId) return { status: 'error', message: 'Not authorized' }
const { contractId, betId } = data
// run as transaction to prevent race conditions
return await firestore.runTransaction(async (transaction) => {
const userDoc = firestore.doc(`users/${userId}`)
const userSnap = await transaction.get(userDoc)
if (!userSnap.exists)
return { status: 'error', message: 'User not found' }
const user = userSnap.data() as User
const contractDoc = firestore.doc(`contracts/${contractId}`)
const contractSnap = await transaction.get(contractDoc)
if (!contractSnap.exists)
return { status: 'error', message: 'Invalid contract' }
const contract = contractSnap.data() as Contract
const betDoc = firestore.doc(`contracts/${contractId}/bets/${betId}`)
const betSnap = await transaction.get(betDoc)
if (!betSnap.exists) return { status: 'error', message: 'Invalid bet' }
const bet = betSnap.data() as Bet
if (bet.isSold) return { status: 'error', message: 'Bet already sold' }
const newBetDoc = firestore
.collection(`contracts/${contractId}/bets`)
.doc()
const { newBet, newPool, newTotalShares, newBalance, creatorFee } =
getSellBetInfo(user, bet, contract, newBetDoc.id)
const creatorDoc = firestore.doc(`users/${contract.creatorId}`)
const creatorSnap = await transaction.get(creatorDoc)
if (creatorSnap.exists) {
const creator = creatorSnap.data() as User
const creatorNewBalance = creator.balance + creatorFee
transaction.update(creatorDoc, { balance: creatorNewBalance })
}
transaction.update(betDoc, { isSold: true })
transaction.create(newBetDoc, newBet)
transaction.update(contractDoc, {
pool: newPool,
totalShares: newTotalShares,
})
transaction.update(userDoc, { balance: newBalance })
return { status: 'success' }
})
}
)
const firestore = admin.firestore()
const getSellBetInfo = (
user: User,
bet: Bet,
contract: Contract,
newBetId: string
) => {
const { id: betId, amount, shares, outcome } = bet
const { YES: yesPool, NO: noPool } = contract.pool
const { YES: yesStart, NO: noStart } = contract.startPool
const { YES: yesShares, NO: noShares } = contract.totalShares
const [y, n, s] = [yesPool, noPool, shares]
const shareValue =
outcome === 'YES'
? // https://www.wolframalpha.com/input/?i=b+%2B+%28b+n%5E2%29%2F%28y+%28-b+%2B+y%29%29+%3D+c+solve+b
(n ** 2 +
s * y +
y ** 2 -
Math.sqrt(
n ** 4 + (s - y) ** 2 * y ** 2 + 2 * n ** 2 * y * (s + y)
)) /
(2 * y)
: (y ** 2 +
s * n +
n ** 2 -
Math.sqrt(
y ** 4 + (s - n) ** 2 * n ** 2 + 2 * y ** 2 * n * (s + n)
)) /
(2 * n)
const startPool = yesStart + noStart
const pool = yesPool + noPool - startPool
const probBefore = yesPool ** 2 / (yesPool ** 2 + noPool ** 2)
const f = pool / (probBefore * yesShares + (1 - probBefore) * noShares)
const myPool = outcome === 'YES' ? yesPool - yesStart : noPool - noStart
const adjShareValue = Math.min(Math.min(1, f) * shareValue, myPool)
const newPool =
outcome === 'YES'
? { YES: yesPool - adjShareValue, NO: noPool }
: { YES: yesPool, NO: noPool - adjShareValue }
const newTotalShares =
outcome === 'YES'
? { YES: yesShares - shares, NO: noShares }
: { YES: yesShares, NO: noShares - shares }
const probAfter = newPool.YES ** 2 / (newPool.YES ** 2 + newPool.NO ** 2)
const creatorFee = CREATOR_FEE * adjShareValue
const saleAmount = (1 - CREATOR_FEE - PLATFORM_FEE) * adjShareValue
console.log(
'SELL M$',
amount,
outcome,
'for M$',
saleAmount,
'M$/share:',
f,
'creator fee: M$',
creatorFee
)
const newBet: Bet = {
id: newBetId,
userId: user.id,
contractId: contract.id,
amount: -adjShareValue,
shares: -shares,
outcome,
probBefore,
probAfter,
createdTime: Date.now(),
sale: {
amount: saleAmount,
betId,
},
}
const newBalance = user.balance + saleAmount
return { newBet, newPool, newTotalShares, newBalance, creatorFee }
}

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@ -2,11 +2,20 @@ export type Bet = {
id: string
userId: string
contractId: string
amount: number // Amount of bet
outcome: 'YES' | 'NO' // Chosen outcome
createdTime: number
amount: number // bet size; negative if SELL bet
outcome: 'YES' | 'NO'
shares: number // dynamic parimutuel pool weight; negative if SELL bet
probBefore: number
probAverage: number
probAfter: number
dpmWeight: number // Dynamic Parimutuel weight
sale?: {
amount: number // amount user makes from sale
betId: string // id of bet being sold
}
isSold?: boolean // true if this BUY bet has been sold
createdTime: number
}

View File

@ -12,7 +12,7 @@ export type Contract = {
startPool: { YES: number; NO: number }
pool: { YES: number; NO: number }
dpmWeights: { YES: number; NO: number }
totalShares: { YES: number; NO: number }
createdTime: number // Milliseconds since epoch
lastUpdatedTime: number // If the question or description was changed

View File

@ -12,9 +12,9 @@ import { formatMoney, formatPercent } from '../lib/util/format'
import { Title } from './title'
import {
getProbability,
getDpmWeight,
calculateShares,
getProbabilityAfterBet,
} from '../lib/calculation/contract'
} from '../lib/calculate'
import { firebaseLogin } from '../lib/firebase/users'
export function BetPanel(props: { contract: Contract; className?: string }) {
@ -84,9 +84,9 @@ export function BetPanel(props: { contract: Contract; className?: string }) {
betChoice,
betAmount ?? 0
)
const dpmWeight = getDpmWeight(contract.pool, betAmount ?? 0, betChoice)
const shares = calculateShares(contract.pool, betAmount ?? 0, betChoice)
const estimatedWinnings = Math.floor((betAmount ?? 0) + dpmWeight)
const estimatedWinnings = Math.floor(shares)
const estimatedReturn = betAmount
? (estimatedWinnings - betAmount) / betAmount
: 0
@ -98,7 +98,7 @@ export function BetPanel(props: { contract: Contract; className?: string }) {
<Col
className={clsx('bg-gray-100 shadow-xl px-8 py-6 rounded-md', className)}
>
<Title className="!mt-0 whitespace-nowrap" text="Place a bet" />
<Title className="!mt-0 whitespace-nowrap" text="Place a trade" />
<div className="mt-2 mb-1 text-sm text-gray-400">Outcome</div>
<YesNoSelector
@ -107,7 +107,7 @@ export function BetPanel(props: { contract: Contract; className?: string }) {
onSelect={(choice) => onBetChoice(choice)}
/>
<div className="mt-3 mb-1 text-sm text-gray-400">Bet amount</div>
<div className="mt-3 mb-1 text-sm text-gray-400">Amount</div>
<Col className="my-2">
<label className="input-group">
<span className="text-sm bg-gray-200">M$</span>
@ -168,18 +168,18 @@ export function BetPanel(props: { contract: Contract; className?: string }) {
)}
onClick={betDisabled ? undefined : submitBet}
>
{isSubmitting ? 'Submitting...' : 'Place bet'}
{isSubmitting ? 'Submitting...' : 'Submit trade'}
</button>
) : (
<button
className="btn mt-4 border-none normal-case text-lg font-medium px-10 bg-gradient-to-r from-teal-500 to-green-500 hover:from-teal-600 hover:to-green-600"
onClick={firebaseLogin}
>
Sign in to bet!
Sign in to trade!
</button>
)}
{wasSubmitted && <div className="mt-4">Bet submitted!</div>}
{wasSubmitted && <div className="mt-4">Trade submitted!</div>}
</Col>
)
}

View File

@ -13,10 +13,13 @@ import { Row } from './layout/row'
import { UserLink } from './user-page'
import {
calculatePayout,
calculateSaleAmount,
currentValue,
resolvedPayout,
} from '../lib/calculation/contract'
} from '../lib/calculate'
import clsx from 'clsx'
import { cloudFunction } from '../lib/firebase/api-call'
import { ConfirmationButton } from './confirmation-button'
export function BetsList(props: { user: User }) {
const { user } = props
@ -65,19 +68,26 @@ export function BetsList(props: { user: User }) {
contracts,
(contract) => contract.isResolved
)
const currentBets = _.sumBy(unresolved, (contract) =>
_.sumBy(contractBets[contract.id], (bet) => bet.amount)
_.sumBy(contractBets[contract.id], (bet) => {
if (bet.isSold || bet.sale) return 0
return bet.amount
})
)
const currentBetsValue = _.sumBy(unresolved, (contract) =>
_.sumBy(contractBets[contract.id], (bet) => currentValue(contract, bet))
_.sumBy(contractBets[contract.id], (bet) => {
if (bet.isSold || bet.sale) return 0
return currentValue(contract, bet)
})
)
return (
<Col className="mt-6 gap-6">
<Row className="gap-8">
<Col>
<div className="text-sm text-gray-500">Active bets</div>
<div className="text-sm text-gray-500">Currently invested</div>
<div>{formatMoney(currentBets)}</div>
</Col>
<Col>
@ -173,16 +183,17 @@ export function MyBetsSummary(props: {
const { bets, contract, className } = props
const { resolution } = contract
const betsTotal = _.sumBy(bets, (bet) => bet.amount)
const excludeSales = bets.filter((b) => !b.isSold && !b.sale)
const betsTotal = _.sumBy(excludeSales, (bet) => bet.amount)
const betsPayout = resolution
? _.sumBy(bets, (bet) => resolvedPayout(contract, bet))
: 0
const yesWinnings = _.sumBy(bets, (bet) =>
const yesWinnings = _.sumBy(excludeSales, (bet) =>
calculatePayout(contract, bet, 'YES')
)
const noWinnings = _.sumBy(bets, (bet) =>
const noWinnings = _.sumBy(excludeSales, (bet) =>
calculatePayout(contract, bet, 'NO')
)
@ -190,7 +201,7 @@ export function MyBetsSummary(props: {
<Row className={clsx('gap-4 sm:gap-6', className)}>
<Col>
<div className="text-sm text-gray-500 whitespace-nowrap">
Total bets
Amount invested
</div>
<div className="whitespace-nowrap">{formatMoney(betsTotal)}</div>
</Col>
@ -228,6 +239,11 @@ export function ContractBetsTable(props: {
}) {
const { contract, bets, className } = props
const [sales, buys] = _.partition(bets, (bet) => bet.sale)
const salesDict = _.fromPairs(
sales.map((sale) => [sale.sale?.betId ?? '', sale])
)
const { isResolved } = contract
return (
@ -237,15 +253,21 @@ export function ContractBetsTable(props: {
<tr className="p-2">
<th>Date</th>
<th>Outcome</th>
<th>Bet</th>
<th>Amount</th>
<th>Probability</th>
{!isResolved && <th>Est. max payout</th>}
<th>{isResolved ? <>Payout</> : <>Current value</>}</th>
<th></th>
</tr>
</thead>
<tbody>
{bets.map((bet) => (
<BetRow key={bet.id} bet={bet} contract={contract} />
{buys.map((bet) => (
<BetRow
key={bet.id}
bet={bet}
sale={salesDict[bet.id]}
contract={contract}
/>
))}
</tbody>
</table>
@ -253,14 +275,22 @@ export function ContractBetsTable(props: {
)
}
function BetRow(props: { bet: Bet; contract: Contract }) {
const { bet, contract } = props
const { amount, outcome, createdTime, probBefore, probAfter, dpmWeight } = bet
function BetRow(props: { bet: Bet; contract: Contract; sale?: Bet }) {
const { bet, sale, contract } = props
const {
amount,
outcome,
createdTime,
probBefore,
probAfter,
shares,
isSold,
} = bet
const { isResolved } = contract
return (
<tr>
<td>{dayjs(createdTime).format('MMM D, H:mma')}</td>
<td>{dayjs(createdTime).format('MMM D, h:mma')}</td>
<td>
<OutcomeLabel outcome={outcome} />
</td>
@ -268,18 +298,63 @@ function BetRow(props: { bet: Bet; contract: Contract }) {
<td>
{formatPercent(probBefore)} {formatPercent(probAfter)}
</td>
{!isResolved && <td>{formatMoney(amount + dpmWeight)}</td>}
{!isResolved && <td>{formatMoney(shares)}</td>}
<td>
{formatMoney(
isResolved
? resolvedPayout(contract, bet)
: currentValue(contract, bet)
)}
{bet.isSold
? 'N/A'
: formatMoney(
isResolved
? resolvedPayout(contract, bet)
: bet.sale
? bet.sale.amount ?? 0
: currentValue(contract, bet)
)}
</td>
{sale ? (
<td>SOLD for {formatMoney(Math.abs(sale.amount))}</td>
) : (
!isResolved &&
!isSold && (
<td className="text-neutral">
<SellButton contract={contract} bet={bet} />
</td>
)
)}
</tr>
)
}
const sellBet = cloudFunction('sellBet')
function SellButton(props: { contract: Contract; bet: Bet }) {
const { contract, bet } = props
const [isSubmitting, setIsSubmitting] = useState(false)
return (
<ConfirmationButton
id={`sell-${bet.id}`}
openModelBtn={{
className: clsx('btn-sm', isSubmitting && 'btn-disabled loading'),
label: 'Sell',
}}
submitBtn={{ className: 'btn-primary' }}
onSubmit={async () => {
setIsSubmitting(true)
await sellBet({ contractId: contract.id, betId: bet.id })
setIsSubmitting(false)
}}
>
<div className="text-2xl mb-4">Sell</div>
<div>
Do you want to sell your {formatMoney(bet.amount)} position on{' '}
<OutcomeLabel outcome={bet.outcome} /> for{' '}
{formatMoney(calculateSaleAmount(contract, bet))}?
</div>
</ConfirmationButton>
)
}
function OutcomeLabel(props: { outcome: 'YES' | 'NO' | 'CANCEL' }) {
const { outcome } = props

View File

@ -90,7 +90,7 @@ export const ContractOverview = (props: {
}) => {
const { contract, className } = props
const { resolution, creatorId } = contract
const { probPercent, volume } = compute(contract)
const { probPercent, truePool } = compute(contract)
const user = useUser()
const isCreator = user?.id === creatorId
@ -140,7 +140,7 @@ export const ContractOverview = (props: {
<ContractDescription contract={contract} isCreator={isCreator} />
{/* Show a delete button for contracts without any trading */}
{isCreator && volume === 0 && (
{isCreator && truePool === 0 && (
<>
<Spacer h={8} />
<button

View File

@ -17,7 +17,7 @@ import { Linkify } from './linkify'
export function ContractDetails(props: { contract: Contract }) {
const { contract } = props
const { volume, createdDate, resolvedDate } = compute(contract)
const { truePool, createdDate, resolvedDate } = compute(contract)
return (
<Row className="flex-wrap text-sm text-gray-500">
@ -29,7 +29,7 @@ export function ContractDetails(props: { contract: Contract }) {
{resolvedDate ? `${createdDate} - ${resolvedDate}` : createdDate}
</div>
<div className="mx-2"></div>
<div className="whitespace-nowrap">{formatMoney(volume)} volume</div>
<div className="whitespace-nowrap">{formatMoney(truePool)} pool</div>
</Row>
)
}
@ -110,14 +110,14 @@ function ContractsGrid(props: { contracts: Contract[] }) {
)
}
type Sort = 'createdTime' | 'volume' | 'resolved' | 'all'
type Sort = 'createdTime' | 'pool' | 'resolved' | 'all'
export function SearchableGrid(props: {
contracts: Contract[]
defaultSort?: Sort
}) {
const { contracts, defaultSort } = props
const [query, setQuery] = useState('')
const [sort, setSort] = useState(defaultSort || 'volume')
const [sort, setSort] = useState(defaultSort || 'pool')
function check(corpus: String) {
return corpus.toLowerCase().includes(query.toLowerCase())
@ -132,8 +132,8 @@ export function SearchableGrid(props: {
if (sort === 'createdTime' || sort === 'resolved' || sort === 'all') {
matches.sort((a, b) => b.createdTime - a.createdTime)
} else if (sort === 'volume') {
matches.sort((a, b) => compute(b).volume - compute(a).volume)
} else if (sort === 'pool') {
matches.sort((a, b) => compute(b).truePool - compute(a).truePool)
}
if (sort !== 'all') {
@ -159,7 +159,7 @@ export function SearchableGrid(props: {
value={sort}
onChange={(e) => setSort(e.target.value as Sort)}
>
<option value="volume">Most traded</option>
<option value="pool">Most traded</option>
<option value="createdTime">Newest first</option>
<option value="resolved">Resolved</option>
<option value="all">All markets</option>

View File

@ -41,8 +41,8 @@ function getNavigationOptions(user: User, options: { mobile: boolean }) {
]
: []),
{
name: 'Your bets',
href: '/bets',
name: 'Your trades',
href: '/trades',
},
{
name: 'Your markets',
@ -64,7 +64,7 @@ function ProfileSummary(props: { user: User }) {
<div className="rounded-full w-10 h-10 mr-4">
<Image src={user.avatarUrl} width={40} height={40} />
</div>
<div className="truncate" style={{ maxWidth: 175 }}>
<div className="truncate text-left" style={{ maxWidth: 175 }}>
{user.name}
<div className="text-gray-700 text-sm">{formatMoney(user.balance)}</div>
</div>

134
web/lib/calculate.ts Normal file
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@ -0,0 +1,134 @@
import { Bet } from './firebase/bets'
import { Contract } from './firebase/contracts'
const fees = 0.02
export function getProbability(pool: { YES: number; NO: number }) {
const [yesPool, noPool] = [pool.YES, pool.NO]
const numerator = Math.pow(yesPool, 2)
const denominator = Math.pow(yesPool, 2) + Math.pow(noPool, 2)
return numerator / denominator
}
export function getProbabilityAfterBet(
pool: { YES: number; NO: number },
outcome: 'YES' | 'NO',
bet: number
) {
const [YES, NO] = [
pool.YES + (outcome === 'YES' ? bet : 0),
pool.NO + (outcome === 'NO' ? bet : 0),
]
return getProbability({ YES, NO })
}
export function calculateShares(
pool: { YES: number; NO: number },
bet: number,
betChoice: 'YES' | 'NO'
) {
const [yesPool, noPool] = [pool.YES, pool.NO]
return betChoice === 'YES'
? bet + (bet * noPool ** 2) / (yesPool ** 2 + bet * yesPool)
: bet + (bet * yesPool ** 2) / (noPool ** 2 + bet * noPool)
}
export function calculatePayout(
contract: Contract,
bet: Bet,
outcome: 'YES' | 'NO' | 'CANCEL'
) {
const { amount, outcome: betOutcome, shares } = bet
if (outcome === 'CANCEL') return amount
if (betOutcome !== outcome) return 0
const { totalShares } = contract
if (totalShares[outcome] === 0) return 0
const startPool = contract.startPool.YES + contract.startPool.NO
const pool = contract.pool.YES + contract.pool.NO - startPool
return (1 - fees) * (shares / totalShares[outcome]) * pool
}
export function resolvedPayout(contract: Contract, bet: Bet) {
if (contract.resolution)
return calculatePayout(contract, bet, contract.resolution)
throw new Error('Contract was not resolved')
}
export function currentValue(contract: Contract, bet: Bet) {
// const prob = getProbability(contract.pool)
// const yesPayout = calculatePayout(contract, bet, 'YES')
// const noPayout = calculatePayout(contract, bet, 'NO')
// return prob * yesPayout + (1 - prob) * noPayout
const { shares, outcome } = bet
const { YES: yesPool, NO: noPool } = contract.pool
const [y, n, s] = [yesPool, noPool, shares]
const shareValue =
outcome === 'YES'
? // https://www.wolframalpha.com/input/?i=b+%2B+%28b+n%5E2%29%2F%28y+%28-b+%2B+y%29%29+%3D+c+solve+b
(n ** 2 +
s * y +
y ** 2 -
Math.sqrt(
n ** 4 + (s - y) ** 2 * y ** 2 + 2 * n ** 2 * y * (s + y)
)) /
(2 * y)
: (y ** 2 +
s * n +
n ** 2 -
Math.sqrt(
y ** 4 + (s - n) ** 2 * n ** 2 + 2 * y ** 2 * n * (s + n)
)) /
(2 * n)
return (1 - fees) * shareValue
}
export function calculateSaleAmount(contract: Contract, bet: Bet) {
const { shares, outcome } = bet
const { YES: yesPool, NO: noPool } = contract.pool
const { YES: yesStart, NO: noStart } = contract.startPool
const { YES: yesShares, NO: noShares } = contract.totalShares
const [y, n, s] = [yesPool, noPool, shares]
const shareValue =
outcome === 'YES'
? // https://www.wolframalpha.com/input/?i=b+%2B+%28b+n%5E2%29%2F%28y+%28-b+%2B+y%29%29+%3D+c+solve+b
(n ** 2 +
s * y +
y ** 2 -
Math.sqrt(
n ** 4 + (s - y) ** 2 * y ** 2 + 2 * n ** 2 * y * (s + y)
)) /
(2 * y)
: (y ** 2 +
s * n +
n ** 2 -
Math.sqrt(
y ** 4 + (s - n) ** 2 * n ** 2 + 2 * y ** 2 * n * (s + n)
)) /
(2 * n)
const startPool = yesStart + noStart
const pool = yesPool + noPool - startPool
const probBefore = yesPool ** 2 / (yesPool ** 2 + noPool ** 2)
const f = pool / (probBefore * yesShares + (1 - probBefore) * noShares)
const myPool = outcome === 'YES' ? yesPool - yesStart : noPool - noStart
const adjShareValue = Math.min(Math.min(1, f) * shareValue, myPool)
const saleAmount = (1 - fees) * adjShareValue
return saleAmount
}

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@ -1,72 +0,0 @@
import { Bet } from '../firebase/bets'
import { Contract } from '../firebase/contracts'
const fees = 0.02
export function getProbability(pool: { YES: number; NO: number }) {
const [yesPool, noPool] = [pool.YES, pool.NO]
const numerator = Math.pow(yesPool, 2)
const denominator = Math.pow(yesPool, 2) + Math.pow(noPool, 2)
return numerator / denominator
}
export function getProbabilityAfterBet(
pool: { YES: number; NO: number },
outcome: 'YES' | 'NO',
bet: number
) {
const [YES, NO] = [
pool.YES + (outcome === 'YES' ? bet : 0),
pool.NO + (outcome === 'NO' ? bet : 0),
]
return getProbability({ YES, NO })
}
export function getDpmWeight(
pool: { YES: number; NO: number },
bet: number,
betChoice: 'YES' | 'NO'
) {
const [yesPool, noPool] = [pool.YES, pool.NO]
return betChoice === 'YES'
? (bet * Math.pow(noPool, 2)) / (Math.pow(yesPool, 2) + bet * yesPool)
: (bet * Math.pow(yesPool, 2)) / (Math.pow(noPool, 2) + bet * noPool)
}
export function calculatePayout(
contract: Contract,
bet: Bet,
outcome: 'YES' | 'NO' | 'CANCEL'
) {
const { amount, outcome: betOutcome, dpmWeight } = bet
if (outcome === 'CANCEL') return amount
if (betOutcome !== outcome) return 0
let { dpmWeights, pool, startPool } = contract
// Fake data if not set.
if (!dpmWeights) dpmWeights = { YES: 100, NO: 100 }
// Fake data if not set.
if (!pool) pool = { YES: 100, NO: 100 }
const otherOutcome = outcome === 'YES' ? 'NO' : 'YES'
const poolSize = pool[otherOutcome] - startPool[otherOutcome]
return (1 - fees) * (dpmWeight / dpmWeights[outcome]) * poolSize + amount
}
export function resolvedPayout(contract: Contract, bet: Bet) {
if (contract.resolution)
return calculatePayout(contract, bet, contract.resolution)
throw new Error('Contract was not resolved')
}
export function currentValue(contract: Contract, bet: Bet) {
const prob = getProbability(contract.pool)
const yesPayout = calculatePayout(contract, bet, 'YES')
const noPayout = calculatePayout(contract, bet, 'NO')
return prob * yesPayout + (1 - prob) * noPayout
}

View File

@ -0,0 +1,6 @@
import { getFunctions, httpsCallable } from 'firebase/functions'
const functions = getFunctions()
export const cloudFunction = (name: string) => httpsCallable(functions, name)

View File

@ -11,12 +11,21 @@ export type Bet = {
id: string
userId: string
contractId: string
amount: number // Amount of bet
outcome: 'YES' | 'NO' // Chosen outcome
dpmWeight: number // Dynamic Parimutuel weight
amount: number // bet size; negative if SELL bet
outcome: 'YES' | 'NO'
shares: number // dynamic parimutuel pool weight; negative if SELL bet
probBefore: number
probAverage: number
probAfter: number
sale?: {
amount: number // amount user makes from sale
betId: string // id of bet being sold
}
isSold?: boolean // true if this BUY bet has been sold
createdTime: number
}

View File

@ -30,7 +30,7 @@ export type Contract = {
startPool: { YES: number; NO: number }
pool: { YES: number; NO: number }
dpmWeights: { YES: number; NO: number }
totalShares: { YES: number; NO: number }
createdTime: number // Milliseconds since epoch
lastUpdatedTime: number // If the question or description was changed
@ -48,7 +48,7 @@ export function path(contract: Contract) {
export function compute(contract: Contract) {
const { pool, startPool, createdTime, resolutionTime, isResolved } = contract
const volume = pool.YES + pool.NO - startPool.YES - startPool.NO
const truePool = pool.YES + pool.NO - startPool.YES - startPool.NO
const prob = pool.YES ** 2 / (pool.YES ** 2 + pool.NO ** 2)
const probPercent = Math.round(prob * 100) + '%'
const startProb =
@ -57,7 +57,7 @@ export function compute(contract: Contract) {
const resolvedDate = isResolved
? dayjs(resolutionTime).format('MMM D')
: undefined
return { volume, probPercent, startProb, createdDate, resolvedDate }
return { truePool, probPercent, startProb, createdDate, resolvedDate }
}
const db = getFirestore(app)

View File

@ -1,24 +1,28 @@
import { getFirestore } from '@firebase/firestore'
import { initializeApp } from 'firebase/app'
const firebaseConfig = {
apiKey: 'AIzaSyDp3J57vLeAZCzxLD-vcPaGIkAmBoGOSYw',
authDomain: 'mantic-markets.firebaseapp.com',
projectId: 'mantic-markets',
storageBucket: 'mantic-markets.appspot.com',
messagingSenderId: '128925704902',
appId: '1:128925704902:web:f61f86944d8ffa2a642dc7',
measurementId: 'G-SSFK1Q138D',
}
export const isProd = process.env.NODE_ENV === 'production'
const firebaseConfig = isProd
? {
apiKey: 'AIzaSyDp3J57vLeAZCzxLD-vcPaGIkAmBoGOSYw',
authDomain: 'mantic-markets.firebaseapp.com',
projectId: 'mantic-markets',
storageBucket: 'mantic-markets.appspot.com',
messagingSenderId: '128925704902',
appId: '1:128925704902:web:f61f86944d8ffa2a642dc7',
measurementId: 'G-SSFK1Q138D',
}
: {
apiKey: 'AIzaSyBoq3rzUa8Ekyo3ZaTnlycQYPRCA26VpOw',
authDomain: 'dev-mantic-markets.firebaseapp.com',
projectId: 'dev-mantic-markets',
storageBucket: 'dev-mantic-markets.appspot.com',
messagingSenderId: '134303100058',
appId: '1:134303100058:web:27f9ea8b83347251f80323',
measurementId: 'G-YJC9E37P37',
}
// Initialize Firebase
export const app = initializeApp(firebaseConfig)
export const db = getFirestore(app)
// try {
// // Note: this is still throwing a console error atm...
// import('firebase/analytics').then((analytics) => {
// analytics.getAnalytics(app)
// })
// } catch (e) {
// console.warn('Analytics were blocked')
// }

View File

@ -2,7 +2,6 @@ import {
Contract,
getContractFromSlug,
pushNewContract,
setContract,
} from '../firebase/contracts'
import { User } from '../firebase/users'
import { randomString } from '../util/random-string'
@ -38,7 +37,7 @@ export async function createContract(
startPool: { YES: startYes, NO: startNo },
pool: { YES: startYes, NO: startNo },
dpmWeights: { YES: 0, NO: 0 },
totalShares: { YES: 0, NO: 0 },
isResolved: false,
// TODO: Set create time to Firestore timestamp
@ -49,8 +48,8 @@ export async function createContract(
return await pushNewContract(contract)
}
export function calcStartPool(initialProb: number, initialCapital = 200) {
const p = initialProb / 100.0
export function calcStartPool(initialProbInt: number, initialCapital = 200) {
const p = initialProbInt / 100.0
const startYes =
p === 0.5

View File

@ -21,10 +21,13 @@ function makeWeights(bids: Bid[]) {
// First pass: calculate all the weights
for (const { yesBid, noBid } of bids) {
const yesWeight =
(yesBid * Math.pow(noPot, 2)) / (Math.pow(yesPot, 2) + yesBid * yesPot) ||
0
yesBid +
(yesBid * Math.pow(noPot, 2)) /
(Math.pow(yesPot, 2) + yesBid * yesPot) || 0
const noWeight =
(noBid * Math.pow(yesPot, 2)) / (Math.pow(noPot, 2) + noBid * noPot) || 0
noBid +
(noBid * Math.pow(yesPot, 2)) / (Math.pow(noPot, 2) + noBid * noPot) ||
0
// Note: Need to calculate weights BEFORE updating pot
yesPot += yesBid
@ -53,15 +56,15 @@ export function makeEntries(bids: Bid[]): Entry[] {
const yesWeightsSum = weights.reduce((sum, entry) => sum + entry.yesWeight, 0)
const noWeightsSum = weights.reduce((sum, entry) => sum + entry.noWeight, 0)
const potSize = yesPot + noPot - YES_SEED - NO_SEED
// Second pass: calculate all the payouts
const entries: Entry[] = []
for (const weight of weights) {
const { yesBid, noBid, yesWeight, noWeight } = weight
// Payout: You get your initial bid back, as well as your share of the
// (noPot - seed) according to your yesWeight
const yesPayout = yesBid + (yesWeight / yesWeightsSum) * (noPot - NO_SEED)
const noPayout = noBid + (noWeight / noWeightsSum) * (yesPot - YES_SEED)
const yesPayout = (yesWeight / yesWeightsSum) * potSize
const noPayout = (noWeight / noWeightsSum) * potSize
const yesReturn = (yesPayout - yesBid) / yesBid
const noReturn = (noPayout - noBid) / noBid
entries.push({ ...weight, yesPayout, noPayout, yesReturn, noReturn })

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@ -6,11 +6,11 @@ const formatter = new Intl.NumberFormat('en-US', {
})
export function formatMoney(amount: number) {
return 'M$ ' + formatter.format(amount).substring(1)
return 'M$ ' + formatter.format(amount).replace('$', '')
}
export function formatWithCommas(amount: number) {
return formatter.format(amount).substring(1)
return formatter.format(amount).replace('$', '')
}
export function formatPercent(zeroToOne: number) {

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@ -97,7 +97,7 @@ function BetsSection(props: { contract: Contract; user: User | null }) {
return (
<div>
<Title text="Your bets" />
<Title text="Your trades" />
<MyBetsSummary contract={contract} bets={userBets} />
<Spacer h={6} />
<ContractBetsTable contract={contract} bets={userBets} />

View File

@ -162,8 +162,8 @@ function Contents() {
</p>
<h3 id="how-are-markets-resolved-">How are markets resolved?</h3>
<p>
The creator of the prediction market decides the outcome and earns 0.5%
of the trade volume for their effort.
The creator of the prediction market decides the outcome and earns 1% of
the betting pool for their effort.
</p>
<p>
This simple resolution mechanism has surprising benefits in allowing a

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@ -86,7 +86,7 @@ function TableRowEnd(props: { entry: Entry | null; isNew?: boolean }) {
return (
<>
<td>{(entry.prob * 100).toFixed(1)}%</td>
<td>${(entry.yesBid + entry.yesWeight).toFixed(0)}</td>
<td>${entry.yesWeight.toFixed(0)}</td>
{!props.isNew && (
<>
<td>${entry.yesPayout.toFixed(0)}</td>
@ -99,7 +99,7 @@ function TableRowEnd(props: { entry: Entry | null; isNew?: boolean }) {
return (
<>
<td>{(entry.prob * 100).toFixed(1)}%</td>
<td>${(entry.noBid + entry.noWeight).toFixed(0)}</td>
<td>${entry.noWeight.toFixed(0)}</td>
{!props.isNew && (
<>
<td>${entry.noPayout.toFixed(0)}</td>
@ -149,9 +149,9 @@ function NewBidTable(props: {
function randomBid() {
const bidType = Math.random() < 0.5 ? 'YES' : 'NO'
const p = bidType === 'YES' ? nextEntry.prob : 1 - nextEntry.prob
// const p = bidType === 'YES' ? nextEntry.prob : 1 - nextEntry.prob
const amount = Math.round(p * Math.random() * 300) + 1
const amount = Math.floor(Math.random() * 300) + 1
const bid = makeBid(bidType, amount)
bids.splice(steps, 0, bid)
@ -238,7 +238,7 @@ function NewBidTable(props: {
// Show a hello world React page
export default function Simulator() {
const [steps, setSteps] = useState(1)
const [bids, setBids] = useState([{ yesBid: 550, noBid: 450 }])
const [bids, setBids] = useState([{ yesBid: 100, noBid: 100 }])
const entries = useMemo(
() => makeEntries(bids.slice(0, steps)),

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@ -4,13 +4,13 @@ import { SEO } from '../components/SEO'
import { Title } from '../components/title'
import { useUser } from '../hooks/use-user'
export default function BetsPage() {
export default function TradesPage() {
const user = useUser()
return (
<Page>
<SEO title="Your bets" description="Your bets" url="/bets" />
<Title text="Your bets" />
<SEO title="Your trades" description="Your trades" url="/trades" />
<Title text="Your trades" />
{user && <BetsList user={user} />}
</Page>
)