diff --git a/common/add-liquidity.ts b/common/add-liquidity.ts
index 254b8936..9271bbbf 100644
--- a/common/add-liquidity.ts
+++ b/common/add-liquidity.ts
@@ -1,10 +1,9 @@
 import { addCpmmLiquidity, getCpmmLiquidity } from './calculate-cpmm'
 import { CPMMContract } from './contract'
 import { LiquidityProvision } from './liquidity-provision'
-import { User } from './user'
 
 export const getNewLiquidityProvision = (
-  user: User,
+  userId: string,
   amount: number,
   contract: CPMMContract,
   newLiquidityProvisionId: string
@@ -18,7 +17,7 @@ export const getNewLiquidityProvision = (
 
   const newLiquidityProvision: LiquidityProvision = {
     id: newLiquidityProvisionId,
-    userId: user.id,
+    userId: userId,
     contractId: contract.id,
     amount,
     pool: newPool,
diff --git a/common/antes.ts b/common/antes.ts
index d4e624b1..ba7c95e8 100644
--- a/common/antes.ts
+++ b/common/antes.ts
@@ -16,6 +16,8 @@ import { Answer } from './answer'
 export const HOUSE_LIQUIDITY_PROVIDER_ID = 'IPTOzEqrpkWmEzh6hwvAyY9PqFb2' // @ManifoldMarkets' id
 export const DEV_HOUSE_LIQUIDITY_PROVIDER_ID = '94YYTk1AFWfbWMpfYcvnnwI1veP2' // @ManifoldMarkets' id
 
+export const UNIQUE_BETTOR_LIQUIDITY_AMOUNT = 20
+
 export function getCpmmInitialLiquidity(
   providerId: string,
   contract: CPMMBinaryContract,
diff --git a/functions/src/add-liquidity.ts b/functions/src/add-liquidity.ts
index 6746486e..e6090111 100644
--- a/functions/src/add-liquidity.ts
+++ b/functions/src/add-liquidity.ts
@@ -1,11 +1,16 @@
 import * as admin from 'firebase-admin'
 import { z } from 'zod'
 
-import { Contract } from '../../common/contract'
+import { Contract, CPMMContract } from '../../common/contract'
 import { User } from '../../common/user'
 import { removeUndefinedProps } from '../../common/util/object'
 import { getNewLiquidityProvision } from '../../common/add-liquidity'
 import { APIError, newEndpoint, validate } from './api'
+import {
+  DEV_HOUSE_LIQUIDITY_PROVIDER_ID,
+  HOUSE_LIQUIDITY_PROVIDER_ID,
+} from '../../common/antes'
+import { isProd } from './utils'
 
 const bodySchema = z.object({
   contractId: z.string(),
@@ -47,7 +52,7 @@ export const addliquidity = newEndpoint({}, async (req, auth) => {
 
     const { newLiquidityProvision, newPool, newP, newTotalLiquidity } =
       getNewLiquidityProvision(
-        user,
+        user.id,
         amount,
         contract,
         newLiquidityProvisionDoc.id
@@ -88,3 +93,41 @@ export const addliquidity = newEndpoint({}, async (req, auth) => {
 })
 
 const firestore = admin.firestore()
+
+export const addHouseLiquidity = (contract: CPMMContract, amount: number) => {
+  return firestore.runTransaction(async (transaction) => {
+    const newLiquidityProvisionDoc = firestore
+      .collection(`contracts/${contract.id}/liquidity`)
+      .doc()
+
+    const providerId = isProd()
+      ? HOUSE_LIQUIDITY_PROVIDER_ID
+      : DEV_HOUSE_LIQUIDITY_PROVIDER_ID
+
+    const { newLiquidityProvision, newPool, newP, newTotalLiquidity } =
+      getNewLiquidityProvision(
+        providerId,
+        amount,
+        contract,
+        newLiquidityProvisionDoc.id
+      )
+
+    if (newP !== undefined && !isFinite(newP)) {
+      throw new APIError(
+        500,
+        'Liquidity injection rejected due to overflow error.'
+      )
+    }
+
+    transaction.update(
+      firestore.doc(`contracts/${contract.id}`),
+      removeUndefinedProps({
+        pool: newPool,
+        p: newP,
+        totalLiquidity: newTotalLiquidity,
+      })
+    )
+
+    transaction.create(newLiquidityProvisionDoc, newLiquidityProvision)
+  })
+}
diff --git a/functions/src/on-create-bet.ts b/functions/src/on-create-bet.ts
index f2c6b51a..6b5f7eac 100644
--- a/functions/src/on-create-bet.ts
+++ b/functions/src/on-create-bet.ts
@@ -24,6 +24,8 @@ import {
 } from '../../common/antes'
 import { APIError } from '../../common/api'
 import { User } from '../../common/user'
+import { UNIQUE_BETTOR_LIQUIDITY_AMOUNT } from '../../common/antes'
+import { addHouseLiquidity } from './add-liquidity'
 
 const firestore = admin.firestore()
 const BONUS_START_DATE = new Date('2022-07-13T15:30:00.000Z').getTime()
@@ -149,18 +151,23 @@ const updateUniqueBettorsAndGiveCreatorBonus = async (
   }
 
   const isNewUniqueBettor = !previousUniqueBettorIds.includes(bettor.id)
-
   const newUniqueBettorIds = uniq([...previousUniqueBettorIds, bettor.id])
+
   // Update contract unique bettors
   if (!contract.uniqueBettorIds || isNewUniqueBettor) {
     log(`Got ${previousUniqueBettorIds} unique bettors`)
     isNewUniqueBettor && log(`And a new unique bettor ${bettor.id}`)
+
     await firestore.collection(`contracts`).doc(contract.id).update({
       uniqueBettorIds: newUniqueBettorIds,
       uniqueBettorCount: newUniqueBettorIds.length,
     })
   }
 
+  if (contract.mechanism === 'cpmm-1' && isNewUniqueBettor) {
+    await addHouseLiquidity(contract, UNIQUE_BETTOR_LIQUIDITY_AMOUNT)
+  }
+
   // No need to give a bonus for the creator's bet
   if (!isNewUniqueBettor || bettor.id == contract.creatorId) return
 
diff --git a/functions/src/on-create-liquidity-provision.ts b/functions/src/on-create-liquidity-provision.ts
index 3a1e551f..54da7fd9 100644
--- a/functions/src/on-create-liquidity-provision.ts
+++ b/functions/src/on-create-liquidity-provision.ts
@@ -7,6 +7,7 @@ import { FIXED_ANTE } from '../../common/economy'
 import {
   DEV_HOUSE_LIQUIDITY_PROVIDER_ID,
   HOUSE_LIQUIDITY_PROVIDER_ID,
+  UNIQUE_BETTOR_LIQUIDITY_AMOUNT,
 } from '../../common/antes'
 
 export const onCreateLiquidityProvision = functions.firestore
@@ -17,9 +18,11 @@ export const onCreateLiquidityProvision = functions.firestore
 
     // Ignore Manifold Markets liquidity for now - users see a notification for free market liquidity provision
     if (
-      (liquidity.userId === HOUSE_LIQUIDITY_PROVIDER_ID ||
+      liquidity.isAnte ||
+      ((liquidity.userId === HOUSE_LIQUIDITY_PROVIDER_ID ||
         liquidity.userId === DEV_HOUSE_LIQUIDITY_PROVIDER_ID) &&
-      liquidity.amount === FIXED_ANTE
+        (liquidity.amount === FIXED_ANTE ||
+          liquidity.amount === UNIQUE_BETTOR_LIQUIDITY_AMOUNT))
     )
       return