diff --git a/common/group.ts b/common/group.ts
index 8f5728d3..cb6660e8 100644
--- a/common/group.ts
+++ b/common/group.ts
@@ -39,3 +39,4 @@ export type GroupLink = {
   createdTime: number
   userId?: string
 }
+export type GroupContractDoc = { contractId: string; createdTime: number }
diff --git a/functions/src/on-update-contract.ts b/functions/src/on-update-contract.ts
index 301d6286..1e3418fa 100644
--- a/functions/src/on-update-contract.ts
+++ b/functions/src/on-update-contract.ts
@@ -2,6 +2,8 @@ import * as functions from 'firebase-functions'
 import { getUser } from './utils'
 import { createCommentOrAnswerOrUpdatedContractNotification } from './create-notification'
 import { Contract } from '../../common/contract'
+import { GroupContractDoc } from '../../common/group'
+import * as admin from 'firebase-admin'
 
 export const onUpdateContract = functions.firestore
   .document('contracts/{contractId}')
@@ -9,17 +11,14 @@ export const onUpdateContract = functions.firestore
     const contract = change.after.data() as Contract
     const previousContract = change.before.data() as Contract
     const { eventId } = context
-    const { openCommentBounties, closeTime, question } = contract
+    const { closeTime, question } = contract
 
-    if (
-      !previousContract.isResolved &&
-      contract.isResolved &&
-      (openCommentBounties ?? 0) > 0
-    ) {
+    if (!previousContract.isResolved && contract.isResolved) {
       // No need to notify users of resolution, that's handled in resolve-market
       return
-    }
-    if (
+    } else if (previousContract.groupSlugs !== contract.groupSlugs) {
+      await handleContractGroupUpdated(previousContract, contract)
+    } else if (
       previousContract.closeTime !== closeTime ||
       previousContract.question !== question
     ) {
@@ -51,3 +50,43 @@ async function handleUpdatedCloseTime(
     contract
   )
 }
+
+async function handleContractGroupUpdated(
+  previousContract: Contract,
+  contract: Contract
+) {
+  const prevLength = previousContract.groupSlugs?.length ?? 0
+  const newLength = contract.groupSlugs?.length ?? 0
+  if (prevLength < newLength) {
+    // Contract was added to a new group
+    const groupId = contract.groupLinks?.find(
+      (link) =>
+        !previousContract.groupLinks
+          ?.map((l) => l.groupId)
+          .includes(link.groupId)
+    )?.groupId
+    if (!groupId) throw new Error('Could not find new group id')
+
+    await firestore
+      .collection(`groups/${groupId}/groupContracts`)
+      .doc(contract.id)
+      .set({
+        contractId: contract.id,
+        createdTime: Date.now(),
+      } as GroupContractDoc)
+  }
+  if (prevLength > newLength) {
+    // Contract was removed from a group
+    const groupId = previousContract.groupLinks?.find(
+      (link) =>
+        !contract.groupLinks?.map((l) => l.groupId).includes(link.groupId)
+    )?.groupId
+    if (!groupId) throw new Error('Could not find old group id')
+
+    await firestore
+      .collection(`groups/${groupId}/groupContracts`)
+      .doc(contract.id)
+      .delete()
+  }
+}
+const firestore = admin.firestore()
diff --git a/functions/src/scripts/update-groups.ts b/functions/src/scripts/update-groups.ts
index fc402292..56a9f399 100644
--- a/functions/src/scripts/update-groups.ts
+++ b/functions/src/scripts/update-groups.ts
@@ -89,17 +89,20 @@ const getGroups = async () => {
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 async function updateTotalContractsAndMembers() {
   const groups = await getGroups()
-  for (const group of groups) {
-    log('updating group total contracts and members', group.slug)
-    const groupRef = admin.firestore().collection('groups').doc(group.id)
-    const totalMembers = (await groupRef.collection('groupMembers').get()).size
-    const totalContracts = (await groupRef.collection('groupContracts').get())
-      .size
-    await groupRef.update({
-      totalMembers,
-      totalContracts,
+  await Promise.all(
+    groups.map(async (group) => {
+      log('updating group total contracts and members', group.slug)
+      const groupRef = admin.firestore().collection('groups').doc(group.id)
+      const totalMembers = (await groupRef.collection('groupMembers').get())
+        .size
+      const totalContracts = (await groupRef.collection('groupContracts').get())
+        .size
+      await groupRef.update({
+        totalMembers,
+        totalContracts,
+      })
     })
-  }
+  )
 }
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 async function removeUnusedMemberAndContractFields() {
@@ -117,6 +120,6 @@ async function removeUnusedMemberAndContractFields() {
 if (require.main === module) {
   initAdmin()
   // convertGroupFieldsToGroupDocuments()
-  // updateTotalContractsAndMembers()
-  removeUnusedMemberAndContractFields()
+  updateTotalContractsAndMembers()
+  // removeUnusedMemberAndContractFields()
 }
diff --git a/web/lib/firebase/groups.ts b/web/lib/firebase/groups.ts
index 17e41c53..6bfc4e85 100644
--- a/web/lib/firebase/groups.ts
+++ b/web/lib/firebase/groups.ts
@@ -191,6 +191,7 @@ export async function leaveGroup(group: Group, userId: string): Promise<void> {
   return await deleteDoc(memberDoc)
 }
 
+// TODO: This doesn't check if the user has permission to do this
 export async function addContractToGroup(
   group: Group,
   contract: Contract,
@@ -211,15 +212,9 @@ export async function addContractToGroup(
     groupSlugs: uniq([...(contract.groupSlugs ?? []), group.slug]),
     groupLinks: newGroupLinks,
   })
-
-  // create new contract document in groupContracts collection
-  const contractDoc = doc(groupContracts(group.id), contract.id)
-  await setDoc(contractDoc, {
-    contractId: contract.id,
-    createdTime: Date.now(),
-  })
 }
 
+// TODO: This doesn't check if the user has permission to do this
 export async function removeContractFromGroup(
   group: Group,
   contract: Contract
@@ -234,10 +229,6 @@ export async function removeContractFromGroup(
       groupLinks: newGroupLinks ?? [],
     })
   }
-
-  // delete the contract document in groupContracts collection
-  const contractDoc = doc(groupContracts(group.id), contract.id)
-  await deleteDoc(contractDoc)
 }
 
 export function getGroupLinkToDisplay(contract: Contract) {