diff --git a/common/user.ts b/common/user.ts
index ccaf2414..73186ac8 100644
--- a/common/user.ts
+++ b/common/user.ts
@@ -6,6 +6,13 @@ export type User = {
   username: string
   avatarUrl?: string
 
+  // For their user page
+  bio?: string
+  bannerUrl?: string
+  website?: string
+  twitterHandle?: string
+  discordHandle?: string
+
   balance: number
   totalDeposits: number
   totalPnLCached: number
diff --git a/common/util/random.ts b/common/util/random.ts
index ce2bc54a..740379e5 100644
--- a/common/util/random.ts
+++ b/common/util/random.ts
@@ -3,22 +3,22 @@ export const randomString = (length = 12) =>
     .toString(16)
     .substring(2, length + 2)
 
+export function genHash(str: string) {
+  // xmur3
+  for (var i = 0, h = 1779033703 ^ str.length; i < str.length; i++) {
+    h = Math.imul(h ^ str.charCodeAt(i), 3432918353)
+    h = (h << 13) | (h >>> 19)
+  }
+  return function () {
+    h = Math.imul(h ^ (h >>> 16), 2246822507)
+    h = Math.imul(h ^ (h >>> 13), 3266489909)
+    return (h ^= h >>> 16) >>> 0
+  }
+}
+
 export function createRNG(seed: string) {
   // https://stackoverflow.com/a/47593316/1592933
 
-  function genHash(str: string) {
-    // xmur3
-    for (var i = 0, h = 1779033703 ^ str.length; i < str.length; i++) {
-      h = Math.imul(h ^ str.charCodeAt(i), 3432918353)
-      h = (h << 13) | (h >>> 19)
-    }
-    return function () {
-      h = Math.imul(h ^ (h >>> 16), 2246822507)
-      h = Math.imul(h ^ (h >>> 13), 3266489909)
-      return (h ^= h >>> 16) >>> 0
-    }
-  }
-
   const gen = genHash(seed)
   let [a, b, c, d] = [gen(), gen(), gen(), gen()]
 
diff --git a/firestore.rules b/firestore.rules
index a626ce1f..e766f15f 100644
--- a/firestore.rules
+++ b/firestore.rules
@@ -13,6 +13,9 @@ service cloud.firestore {
 
     match /users/{userId} {
       allow read;
+      allow update: if resource.data.id == request.auth.uid 
+        || request.resource.data.diff(resource.data).affectedKeys()
+            .hasOnly(['bio', 'bannerUrl', 'website', 'twitterHandle', 'discordHandle']);
     }
 
     match /private-users/{userId} {
diff --git a/web/components/site-link.tsx b/web/components/site-link.tsx
index 79f43118..c59e106a 100644
--- a/web/components/site-link.tsx
+++ b/web/components/site-link.tsx
@@ -12,10 +12,11 @@ export const SiteLink = (props: {
     <a
       href={href}
       className={clsx(
-        'break-words z-10 hover:underline hover:decoration-indigo-400 hover:decoration-2',
+        'z-10 break-words hover:underline hover:decoration-indigo-400 hover:decoration-2',
         className
       )}
       style={{ /* For iOS safari */ wordBreak: 'break-word' }}
+      target="_blank"
       onClick={(e) => e.stopPropagation()}
     >
       {children}
@@ -24,7 +25,7 @@ export const SiteLink = (props: {
     <Link href={href}>
       <a
         className={clsx(
-          'break-words z-10 hover:underline hover:decoration-indigo-400 hover:decoration-2',
+          'z-10 break-words hover:underline hover:decoration-indigo-400 hover:decoration-2',
           className
         )}
         style={{ /* For iOS safari */ wordBreak: 'break-word' }}
diff --git a/web/components/user-page.tsx b/web/components/user-page.tsx
index 2c8177c5..5dda5630 100644
--- a/web/components/user-page.tsx
+++ b/web/components/user-page.tsx
@@ -9,6 +9,8 @@ import { Col } from './layout/col'
 import { Linkify } from './linkify'
 import { Spacer } from './layout/spacer'
 import { Row } from './layout/row'
+import { LinkIcon } from '@heroicons/react/solid'
+import { genHash } from '../../common/util/random'
 
 export function UserLink(props: {
   name: string
@@ -33,10 +35,9 @@ export function UserPage(props: { user: User; currentUser?: User }) {
 
   const possesive = isCurrentUser ? 'Your ' : `${user.name}'s `
 
-  const bannerImageUrl =
-    'https://images.unsplash.com/photo-1548197253-652ffe79752c?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1975&q=80'
+  const bannerUrl = user.bannerUrl ?? defaultBannerUrl(user.id)
 
-  const placeholderBio = `Hi! Always happy to chat; reach out at akrolsmir@gmail.com, or find a time on https://calendly.com/austinchen/manifold !`
+  const placeholderBio = `I... haven't gotten around to writing a bio yet 😛`
 
   return (
     <Page>
@@ -50,10 +51,11 @@ export function UserPage(props: { user: User; currentUser?: User }) {
       <div
         className="h-32 w-full bg-cover bg-center sm:h-40"
         style={{
-          backgroundImage: `url(${bannerImageUrl})`,
+          backgroundImage: `url(${bannerUrl})`,
         }}
       />
       <div className="relative -top-10 left-4">
+        {/* TODO: add a white ring to the avatar */}
         <Avatar username={user.username} avatarUrl={user.avatarUrl} size={20} />
       </div>
 
@@ -64,25 +66,50 @@ export function UserPage(props: { user: User; currentUser?: User }) {
         <Spacer h={4} />
 
         <div>
-          <Linkify text={placeholderBio}></Linkify>
+          <Linkify text={user.bio || placeholderBio}></Linkify>
         </div>
         <Spacer h={4} />
 
-        <Row className="gap-4">
-          <a href={`https://twitter.com/akrolsmir`}>
-            <Row className="items-center gap-1">
-              <img src="/twitter-logo.svg" className="h-4 w-4" alt="Twitter" />
-              <span className="text-sm text-gray-500">akrolsmir</span>
-            </Row>
-          </a>
+        <Col className="sm:flex-row sm:gap-4">
+          {user.website && (
+            <SiteLink href={user.website}>
+              <Row className="items-center gap-1">
+                <LinkIcon className="h-4 w-4" />
+                <span className="text-sm text-gray-500">{user.website}</span>
+              </Row>
+            </SiteLink>
+          )}
 
-          <a href="https://discord.com/invite/eHQBNBqXuh">
-            <Row className="items-center gap-1">
-              <img src="/discord-logo.svg" className="h-4 w-4" alt="Discord" />
-              <span className="text-sm text-gray-500">akrolsmir#4125</span>
-            </Row>
-          </a>
-        </Row>
+          {user.twitterHandle && (
+            <SiteLink href={`https://twitter.com/${user.twitterHandle}`}>
+              <Row className="items-center gap-1">
+                <img
+                  src="/twitter-logo.svg"
+                  className="h-4 w-4"
+                  alt="Twitter"
+                />
+                <span className="text-sm text-gray-500">
+                  {user.twitterHandle}
+                </span>
+              </Row>
+            </SiteLink>
+          )}
+
+          {user.discordHandle && (
+            <SiteLink href="https://discord.com/invite/eHQBNBqXuh">
+              <Row className="items-center gap-1">
+                <img
+                  src="/discord-logo.svg"
+                  className="h-4 w-4"
+                  alt="Discord"
+                />
+                <span className="text-sm text-gray-500">
+                  {user.discordHandle}
+                </span>
+              </Row>
+            </SiteLink>
+          )}
+        </Col>
 
         <Spacer h={10} />
 
@@ -91,3 +118,15 @@ export function UserPage(props: { user: User; currentUser?: User }) {
     </Page>
   )
 }
+
+// Assign each user to a random default banner based on the hash of userId
+export function defaultBannerUrl(userId: string) {
+  const defaultBanner = [
+    'https://images.unsplash.com/photo-1501523460185-2aa5d2a0f981?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=2131&q=80',
+    'https://images.unsplash.com/photo-1458682625221-3a45f8a844c7?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1974&q=80',
+    'https://images.unsplash.com/photo-1558517259-165ae4b10f7f?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=2080&q=80',
+    'https://images.unsplash.com/photo-1563260797-cb5cd70254c8?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=2069&q=80',
+    'https://images.unsplash.com/photo-1603399587513-136aa9398f2d?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1467&q=80',
+  ]
+  return defaultBanner[genHash(userId)() % defaultBanner.length]
+}
diff --git a/web/lib/firebase/users.ts b/web/lib/firebase/users.ts
index 56403358..04d82571 100644
--- a/web/lib/firebase/users.ts
+++ b/web/lib/firebase/users.ts
@@ -9,6 +9,7 @@ import {
   limit,
   getDocs,
   orderBy,
+  updateDoc,
 } from 'firebase/firestore'
 import { getAuth } from 'firebase/auth'
 import { ref, getStorage, uploadBytes, getDownloadURL } from 'firebase/storage'
@@ -21,7 +22,8 @@ import {
 import { app } from './init'
 import { PrivateUser, User } from '../../../common/user'
 import { createUser } from './api-call'
-import { getValue, getValues, listenForValue, listenForValues } from './utils'
+import { getValues, listenForValue, listenForValues } from './utils'
+
 export type { User }
 
 const db = getFirestore(app)
@@ -45,6 +47,10 @@ export async function setUser(userId: string, user: User) {
   await setDoc(doc(db, 'users', userId), user)
 }
 
+export async function updateUser(userId: string, update: Partial<User>) {
+  await updateDoc(doc(db, 'users', userId), { ...update })
+}
+
 export function listenForUser(
   userId: string,
   setUser: (user: User | null) => void
diff --git a/web/pages/profile.tsx b/web/pages/profile.tsx
index 036f2972..34cbe555 100644
--- a/web/pages/profile.tsx
+++ b/web/pages/profile.tsx
@@ -16,6 +16,40 @@ import { changeUserInfo } from '../lib/firebase/api-call'
 import { uploadImage } from '../lib/firebase/storage'
 import { Col } from '../components/layout/col'
 import { Row } from '../components/layout/row'
+import { User } from '../../common/user'
+import { defaultBannerUrl, updateUser } from '../lib/firebase/users'
+
+function EditUserField(props: {
+  user: User
+  field: 'bio' | 'bannerUrl' | 'twitterHandle' | 'discordHandle'
+  label: string
+  isEditing: boolean
+}) {
+  const { user, field, label, isEditing } = props
+  const [value, setValue] = useState(user[field] ?? '')
+
+  async function updateField() {
+    await updateUser(user.id, { [field]: value })
+  }
+
+  return (
+    <div>
+      <label className="label">{label}</label>
+
+      {isEditing ? (
+        <input
+          type="text"
+          className="input input-bordered"
+          value={value}
+          onChange={(e) => setValue(e.target.value || '')}
+          onBlur={updateField}
+        />
+      ) : (
+        <div className="ml-1 break-words text-gray-500">{value || '-'}</div>
+      )}
+    </div>
+  )
+}
 
 export default function ProfilePage() {
   const user = useUser()
@@ -166,6 +200,42 @@ export default function ProfilePage() {
             )}
           </div>
 
+          {user && (
+            <>
+              {/* TODO: Allow users with M$ 2000 of assets to set custom banners */}
+              {/* <EditUserField
+                user={user}
+                field="bannerUrl"
+                label="Banner Url"
+                isEditing={isEditing}
+              /> */}
+              <label className="label">Banner</label>
+              <div
+                className="h-32 w-full bg-cover bg-center sm:h-40"
+                style={{
+                  backgroundImage: `url(${
+                    user.bannerUrl || defaultBannerUrl(user.id)
+                  })`,
+                }}
+              />
+
+              {[
+                ['bio', 'Bio'],
+                ['website', 'Website URL'],
+                ['twitterHandle', 'Twitter'],
+                ['discordHandle', 'Discord'],
+              ].map(([field, label]) => (
+                <EditUserField
+                  user={user}
+                  // @ts-ignore
+                  field={field}
+                  label={label}
+                  isEditing={isEditing}
+                />
+              ))}
+            </>
+          )}
+
           <div>
             <label className="label">Email</label>
             <div className="ml-1 text-gray-500">