diff --git a/functions/src/resolve-market.ts b/functions/src/resolve-market.ts
index 164551bd..4862703f 100644
--- a/functions/src/resolve-market.ts
+++ b/functions/src/resolve-market.ts
@@ -26,7 +26,7 @@ export const resolveMarket = functions
 
       const { outcome, contractId } = data
 
-      if (!['YES', 'NO', 'CANCEL'].includes(outcome))
+      if (!['YES', 'NO', 'MKT', 'CANCEL'].includes(outcome))
         return { status: 'error', message: 'Invalid outcome' }
 
       const contractDoc = firestore.doc(`contracts/${contractId}`)
@@ -155,7 +155,6 @@ const getStandardPayouts = (
   const shareDifferenceSum = _.sumBy(winningBets, (b) => b.shares - b.amount)
 
   const winningsPool = truePool - betSum
-  const fees = PLATFORM_FEE + CREATOR_FEE
 
   const winnerPayouts = winningBets.map((bet) => ({
     userId: bet.userId,
@@ -173,11 +172,53 @@ const getStandardPayouts = (
 const getMktPayouts = (truePool: number, contract: Contract, bets: Bet[]) => {
   const p =
     contract.pool.YES ** 2 / (contract.pool.YES ** 2 + contract.pool.NO ** 2)
-  console.log('Resolved MKT at p=', p)
+  console.log('Resolved MKT at p=', p, 'pool: $M', truePool)
+
+  const [yesBets, noBets] = _.partition(bets, (bet) => bet.outcome === 'YES')
+
+  const weightedBetTotal =
+    p * _.sumBy(yesBets, (b) => b.amount) +
+    (1 - p) * _.sumBy(noBets, (b) => b.amount)
+
+  if (weightedBetTotal >= truePool) {
+    return bets.map((bet) => ({
+      userId: bet.userId,
+      payout:
+        (((bet.outcome === 'YES' ? p : 1 - p) * bet.amount) /
+          weightedBetTotal) *
+        truePool,
+    }))
+  }
+
+  const winningsPool = truePool - weightedBetTotal
+
+  const weightedShareTotal =
+    p * _.sumBy(yesBets, (b) => b.shares - b.amount) +
+    (1 - p) * _.sumBy(noBets, (b) => b.shares - b.amount)
+
+  const yesPayouts = yesBets.map((bet) => ({
+    userId: bet.userId,
+    payout:
+      (1 - fees) *
+      (p * bet.amount +
+        ((p * (bet.shares - bet.amount)) / weightedShareTotal) * winningsPool),
+  }))
+
+  const noPayouts = noBets.map((bet) => ({
+    userId: bet.userId,
+    payout:
+      (1 - fees) *
+      ((1 - p) * bet.amount +
+        (((1 - p) * (bet.shares - bet.amount)) / weightedShareTotal) *
+          winningsPool),
+  }))
+
+  const creatorPayout = CREATOR_FEE * truePool
 
   return [
-    ...getStandardPayouts('YES', p * truePool, contract, bets),
-    ...getStandardPayouts('NO', (1 - p) * truePool, contract, bets),
+    ...yesPayouts,
+    ...noPayouts,
+    { userId: contract.creatorId, payout: creatorPayout },
   ]
 }
 
@@ -192,3 +233,5 @@ const payUser = ([userId, payout]: [string, number]) => {
     transaction.update(userDoc, { balance: newUserBalance })
   })
 }
+
+const fees = PLATFORM_FEE + CREATOR_FEE
diff --git a/functions/src/scripts/recalculate.ts b/functions/src/scripts/recalculate.ts
new file mode 100644
index 00000000..103152c9
--- /dev/null
+++ b/functions/src/scripts/recalculate.ts
@@ -0,0 +1,61 @@
+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/dev-mantic-markets-firebase-adminsdk-sir5m-b2d27f8970.json')
+
+admin.initializeApp({
+  credential: admin.credential.cert(serviceAccount),
+})
+const firestore = admin.firestore()
+
+async function recalculateContract(contractRef: DocRef, contract: Contract) {
+  const bets = await contractRef
+    .collection('bets')
+    .get()
+    .then((snap) => snap.docs.map((bet) => bet.data() as Bet))
+
+  const openBets = bets.filter((b) => !b.isSold && !b.sale)
+
+  const totalShares = {
+    YES: _.sumBy(openBets, (bet) => (bet.outcome === 'YES' ? bet.shares : 0)),
+    NO: _.sumBy(openBets, (bet) => (bet.outcome === 'NO' ? bet.shares : 0)),
+  }
+
+  const totalBets = {
+    YES: _.sumBy(openBets, (bet) => (bet.outcome === 'YES' ? bet.amount : 0)),
+    NO: _.sumBy(openBets, (bet) => (bet.outcome === 'NO' ? bet.amount : 0)),
+  }
+
+  await contractRef.update({ totalShares, totalBets })
+
+  console.log(
+    'calculating totals for "',
+    contract.question,
+    '" total bets:',
+    totalBets
+  )
+  console.log()
+}
+
+async function migrateContracts() {
+  console.log('Recalculating contract info')
+
+  const snapshot = await firestore.collection('contracts').get()
+  const contracts = snapshot.docs.map((doc) => doc.data() as Contract)
+
+  console.log('Loaded', contracts.length, 'contracts')
+
+  for (const contract of contracts) {
+    const contractRef = firestore.doc(`contracts/${contract.id}`)
+
+    await recalculateContract(contractRef, contract)
+  }
+}
+
+if (require.main === module) migrateContracts().then(() => process.exit())
diff --git a/web/components/bets-list.tsx b/web/components/bets-list.tsx
index 18c74563..29d51346 100644
--- a/web/components/bets-list.tsx
+++ b/web/components/bets-list.tsx
@@ -191,7 +191,7 @@ export function MyBetsSummary(props: {
   const betsTotal = _.sumBy(excludeSales, (bet) => bet.amount)
 
   const betsPayout = resolution
-    ? _.sumBy(bets, (bet) => resolvedPayout(contract, bet))
+    ? _.sumBy(excludeSales, (bet) => resolvedPayout(contract, bet))
     : 0
 
   const yesWinnings = _.sumBy(excludeSales, (bet) =>
@@ -357,11 +357,12 @@ function SellButton(props: { contract: Contract; bet: Bet }) {
   )
 }
 
-function OutcomeLabel(props: { outcome: 'YES' | 'NO' | 'CANCEL' }) {
+function OutcomeLabel(props: { outcome: 'YES' | 'NO' | 'CANCEL' | 'MKT' }) {
   const { outcome } = props
 
   if (outcome === 'YES') return <YesLabel />
   if (outcome === 'NO') return <NoLabel />
+  if (outcome === 'MKT') return <MarketLabel />
   return <CancelLabel />
 }
 
@@ -376,3 +377,7 @@ function NoLabel() {
 function CancelLabel() {
   return <span className="text-yellow-400">N/A</span>
 }
+
+function MarketLabel() {
+  return <span className="text-blue-400">MKT</span>
+}
diff --git a/web/components/contract-overview.tsx b/web/components/contract-overview.tsx
index aa8dfe6c..ec2fc4cb 100644
--- a/web/components/contract-overview.tsx
+++ b/web/components/contract-overview.tsx
@@ -98,6 +98,7 @@ export const ContractOverview = (props: {
   const resolutionColor = {
     YES: 'text-primary',
     NO: 'text-red-400',
+    MKT: 'text-blue-400',
     CANCEL: 'text-yellow-400',
     '': '', // Empty if unresolved
   }[contract.resolution || '']
diff --git a/web/components/contracts-list.tsx b/web/components/contracts-list.tsx
index 07c052b0..dc83bafb 100644
--- a/web/components/contracts-list.tsx
+++ b/web/components/contracts-list.tsx
@@ -44,6 +44,7 @@ function ContractCard(props: { contract: Contract }) {
   const resolutionColor = {
     YES: 'text-primary',
     NO: 'text-red-400',
+    MKT: 'text-blue-400',
     CANCEL: 'text-yellow-400',
     '': '', // Empty if unresolved
   }[contract.resolution || '']
@@ -51,6 +52,7 @@ function ContractCard(props: { contract: Contract }) {
   const resolutionText = {
     YES: 'YES',
     NO: 'NO',
+    MKT: 'MKT',
     CANCEL: 'N/A',
     '': '',
   }[contract.resolution || '']
diff --git a/web/components/resolution-panel.tsx b/web/components/resolution-panel.tsx
index 7f9f74c6..d5ccbfd5 100644
--- a/web/components/resolution-panel.tsx
+++ b/web/components/resolution-panel.tsx
@@ -20,7 +20,9 @@ export function ResolutionPanel(props: {
 }) {
   const { contract, className } = props
 
-  const [outcome, setOutcome] = useState<'YES' | 'NO' | 'CANCEL' | undefined>()
+  const [outcome, setOutcome] = useState<
+    'YES' | 'NO' | 'MKT' | 'CANCEL' | undefined
+  >()
 
   const [isSubmitting, setIsSubmitting] = useState(false)
   const [error, setError] = useState<string | undefined>(undefined)
@@ -48,6 +50,8 @@ export function ResolutionPanel(props: {
       ? 'bg-red-400 hover:bg-red-500'
       : outcome === 'CANCEL'
       ? 'bg-yellow-400 hover:bg-yellow-500'
+      : outcome === 'MKT'
+      ? 'bg-blue-400 hover:bg-blue-500'
       : 'btn-disabled'
 
   return (
@@ -74,6 +78,11 @@ export function ResolutionPanel(props: {
           <>Winnings will be paid out to NO bettors. You earn 1% of the pool.</>
         ) : outcome === 'CANCEL' ? (
           <>The pool will be returned to traders with no fees.</>
+        ) : outcome === 'MKT' ? (
+          <>
+            Traders will be paid out at the current implied probability. You
+            earn 1% of the pool.
+          </>
         ) : (
           <>Resolving this market will immediately pay out traders.</>
         )}
diff --git a/web/components/yes-no-selector.tsx b/web/components/yes-no-selector.tsx
index 391db469..528b199d 100644
--- a/web/components/yes-no-selector.tsx
+++ b/web/components/yes-no-selector.tsx
@@ -1,5 +1,6 @@
 import clsx from 'clsx'
 import React from 'react'
+import { Col } from './layout/col'
 import { Row } from './layout/row'
 
 export function YesNoSelector(props: {
@@ -29,48 +30,60 @@ export function YesNoSelector(props: {
 }
 
 export function YesNoCancelSelector(props: {
-  selected: 'YES' | 'NO' | 'CANCEL' | undefined
-  onSelect: (selected: 'YES' | 'NO' | 'CANCEL') => void
+  selected: 'YES' | 'NO' | 'MKT' | 'CANCEL' | undefined
+  onSelect: (selected: 'YES' | 'NO' | 'MKT' | 'CANCEL') => void
   className?: string
   btnClassName?: string
 }) {
   const { selected, onSelect, className } = props
 
-  const btnClassName = clsx('px-6', props.btnClassName)
+  const btnClassName = clsx('px-6 flex-1', props.btnClassName)
 
   return (
-    <Row className={clsx('space-x-3', className)}>
-      <Button
-        color={selected === 'YES' ? 'green' : 'gray'}
-        onClick={() => onSelect('YES')}
-        className={btnClassName}
-      >
-        YES
-      </Button>
+    <Col>
+      <Row className={clsx('space-x-3 w-full', className)}>
+        <Button
+          color={selected === 'YES' ? 'green' : 'gray'}
+          onClick={() => onSelect('YES')}
+          className={btnClassName}
+        >
+          YES
+        </Button>
 
-      <Button
-        color={selected === 'NO' ? 'red' : 'gray'}
-        onClick={() => onSelect('NO')}
-        className={btnClassName}
-      >
-        NO
-      </Button>
+        <Button
+          color={selected === 'NO' ? 'red' : 'gray'}
+          onClick={() => onSelect('NO')}
+          className={btnClassName}
+        >
+          NO
+        </Button>
+      </Row>
 
-      <Button
-        color={selected === 'CANCEL' ? 'yellow' : 'gray'}
-        onClick={() => onSelect('CANCEL')}
-        className={btnClassName}
-      >
-        N/A
-      </Button>
-    </Row>
+      <Row className={clsx('space-x-3 w-full', className)}>
+        <Button
+          color={selected === 'MKT' ? 'blue' : 'gray'}
+          onClick={() => onSelect('MKT')}
+          className={clsx(btnClassName, 'btn-sm')}
+        >
+          MKT
+        </Button>
+
+        <Button
+          color={selected === 'CANCEL' ? 'yellow' : 'gray'}
+          onClick={() => onSelect('CANCEL')}
+          className={clsx(btnClassName, 'btn-sm')}
+        >
+          N/A
+        </Button>
+      </Row>
+    </Col>
   )
 }
 
 function Button(props: {
   className?: string
   onClick?: () => void
-  color: 'green' | 'red' | 'yellow' | 'gray'
+  color: 'green' | 'red' | 'blue' | 'yellow' | 'gray'
   children?: any
 }) {
   const { className, onClick, children, color } = props
@@ -83,6 +96,7 @@ function Button(props: {
         color === 'green' && 'btn-primary',
         color === 'red' && 'bg-red-400 hover:bg-red-500',
         color === 'yellow' && 'bg-yellow-400 hover:bg-yellow-500',
+        color === 'blue' && 'bg-blue-400 hover:bg-blue-500',
         color === 'gray' && 'text-gray-700 bg-gray-300 hover:bg-gray-400',
         className
       )}
diff --git a/web/lib/calculate.ts b/web/lib/calculate.ts
index 642473df..b265f228 100644
--- a/web/lib/calculate.ts
+++ b/web/lib/calculate.ts
@@ -37,11 +37,13 @@ export function calculateShares(
 export function calculatePayout(
   contract: Contract,
   bet: Bet,
-  outcome: 'YES' | 'NO' | 'CANCEL'
+  outcome: 'YES' | 'NO' | 'CANCEL' | 'MKT'
 ) {
   const { amount, outcome: betOutcome, shares } = bet
 
   if (outcome === 'CANCEL') return amount
+  if (outcome === 'MKT') return calculateMktPayout(contract, bet)
+
   if (betOutcome !== outcome) return 0
 
   const { totalShares, totalBets } = contract
@@ -60,6 +62,34 @@ export function calculatePayout(
   return (1 - fees) * (amount + ((shares - amount) / total) * winningsPool)
 }
 
+function calculateMktPayout(contract: Contract, bet: Bet) {
+  const p =
+    contract.pool.YES ** 2 / (contract.pool.YES ** 2 + contract.pool.NO ** 2)
+  const weightedTotal =
+    p * contract.totalBets.YES + (1 - p) * contract.totalBets.NO
+
+  const startPool = contract.startPool.YES + contract.startPool.NO
+  const truePool = contract.pool.YES + contract.pool.NO - startPool
+
+  const betP = bet.outcome === 'YES' ? p : 1 - p
+
+  if (weightedTotal >= truePool) {
+    return ((betP * bet.amount) / weightedTotal) * truePool
+  }
+
+  const winningsPool = truePool - weightedTotal
+
+  const weightedShareTotal =
+    p * (contract.totalShares.YES - contract.totalBets.YES) +
+    (1 - p) * (contract.totalShares.NO - contract.totalBets.NO)
+
+  return (
+    (1 - fees) *
+    (betP * bet.amount +
+      ((betP * (bet.shares - bet.amount)) / weightedShareTotal) * winningsPool)
+  )
+}
+
 export function resolvedPayout(contract: Contract, bet: Bet) {
   if (contract.resolution)
     return calculatePayout(contract, bet, contract.resolution)