diff --git a/zerver/actions/streams.py b/zerver/actions/streams.py
index 292c94df70..e205e2b493 100644
--- a/zerver/actions/streams.py
+++ b/zerver/actions/streams.py
@@ -328,7 +328,7 @@ def send_subscription_add_events(
         info_by_user[sub_info.user.id].append(sub_info)
 
     stream_ids = {sub_info.stream.id for sub_info in sub_info_list}
-    recent_traffic = get_streams_traffic(stream_ids=stream_ids)
+    recent_traffic = get_streams_traffic(stream_ids=stream_ids, realm=realm)
 
     # We generally only have a few streams, so we compute stream
     # data in its own loop.
diff --git a/zerver/lib/subscription_info.py b/zerver/lib/subscription_info.py
index df1346eecf..971e458073 100644
--- a/zerver/lib/subscription_info.py
+++ b/zerver/lib/subscription_info.py
@@ -109,7 +109,7 @@ def build_stream_dict_for_sub(
     user: UserProfile,
     sub_dict: RawSubscriptionDict,
     raw_stream_dict: RawStreamDict,
-    recent_traffic: Dict[int, int],
+    recent_traffic: Optional[Dict[int, int]],
 ) -> SubscriptionStreamDict:
     # Handle Stream.API_FIELDS
     can_remove_subscribers_group_id = raw_stream_dict["can_remove_subscribers_group_id"]
@@ -145,9 +145,12 @@ def build_stream_dict_for_sub(
     is_announcement_only = raw_stream_dict["stream_post_policy"] == Stream.STREAM_POST_POLICY_ADMINS
 
     # Add a few computed fields not directly from the data models.
-    stream_weekly_traffic = get_average_weekly_stream_traffic(
-        raw_stream_dict["id"], raw_stream_dict["date_created"], recent_traffic
-    )
+    if recent_traffic is not None:
+        stream_weekly_traffic = get_average_weekly_stream_traffic(
+            raw_stream_dict["id"], raw_stream_dict["date_created"], recent_traffic
+        )
+    else:
+        stream_weekly_traffic = None
 
     email_address = encode_email_address_helper(
         raw_stream_dict["name"], raw_stream_dict["email_token"], show_sender=True
@@ -184,7 +187,7 @@ def build_stream_dict_for_sub(
 
 def build_stream_dict_for_never_sub(
     raw_stream_dict: RawStreamDict,
-    recent_traffic: Dict[int, int],
+    recent_traffic: Optional[Dict[int, int]],
 ) -> NeverSubscribedStreamDict:
     can_remove_subscribers_group_id = raw_stream_dict["can_remove_subscribers_group_id"]
     date_created = datetime_to_timestamp(raw_stream_dict["date_created"])
@@ -198,9 +201,13 @@ def build_stream_dict_for_never_sub(
     rendered_description = raw_stream_dict["rendered_description"]
     stream_id = raw_stream_dict["id"]
     stream_post_policy = raw_stream_dict["stream_post_policy"]
-    stream_weekly_traffic = get_average_weekly_stream_traffic(
-        raw_stream_dict["id"], raw_stream_dict["date_created"], recent_traffic
-    )
+
+    if recent_traffic is not None:
+        stream_weekly_traffic = get_average_weekly_stream_traffic(
+            raw_stream_dict["id"], raw_stream_dict["date_created"], recent_traffic
+        )
+    else:
+        stream_weekly_traffic = None
 
     # Backwards-compatibility addition of removed field.
     is_announcement_only = raw_stream_dict["stream_post_policy"] == Stream.STREAM_POST_POLICY_ADMINS
@@ -430,8 +437,7 @@ def gather_subscriptions_helper(
         return recip_id_to_stream_id[sub_dict["recipient_id"]]
 
     traffic_stream_ids = {get_stream_id(sub_dict) for sub_dict in sub_dicts}
-    recent_traffic = get_streams_traffic(stream_ids=traffic_stream_ids)
-    assert recent_traffic is not None
+    recent_traffic = get_streams_traffic(stream_ids=traffic_stream_ids, realm=realm)
 
     # Okay, now we finally get to populating our main results, which
     # will be these three lists.
diff --git a/zerver/tests/test_subs.py b/zerver/tests/test_subs.py
index b57121671b..28274c1b71 100644
--- a/zerver/tests/test_subs.py
+++ b/zerver/tests/test_subs.py
@@ -4967,7 +4967,7 @@ class SubscriptionAPITest(ZulipTestCase):
         # realm. This does generate stream creation events from
         # send_stream_creation_events_for_previously_inaccessible_streams.
         with self.capture_send_event_calls(expected_num_events=num_streams + 1) as events:
-            with self.assert_database_query_count(num_streams + 12):
+            with self.assert_database_query_count(num_streams + 11):
                 self.common_subscribe_to_streams(
                     mit_user,
                     stream_names,
@@ -6249,7 +6249,7 @@ class GetSubscribersTest(ZulipTestCase):
             subdomain="zephyr",
         )
 
-        with self.assert_database_query_count(4):
+        with self.assert_database_query_count(3):
             subscribed_streams, _ = gather_subscriptions(mit_user_profile, include_subscribers=True)
 
         self.assertGreaterEqual(len(subscribed_streams), 2)
@@ -6260,6 +6260,19 @@ class GetSubscribersTest(ZulipTestCase):
                 self.assert_length(sub["subscribers"], len(users_to_subscribe))
             else:
                 self.assert_length(sub["subscribers"], 0)
+            self.assertIsNone(sub["stream_weekly_traffic"])
+
+        # Create a web-public stream to test never_subscried data.
+        self.make_stream("mit_stream_2", realm=mit_user_profile.realm, is_web_public=True)
+        self.make_stream("mit_stream_3", realm=mit_user_profile.realm)
+
+        sub_info = gather_subscriptions_helper(mit_user_profile, include_subscribers=True)
+        never_subscribed_streams = sub_info.never_subscribed
+        # Users in zephyr mirror realm can only access web-public never subscribed streams.
+        self.assert_length(never_subscribed_streams, 1)
+        self.assertEqual(never_subscribed_streams[0]["name"], "mit_stream_2")
+        self.assertTrue(never_subscribed_streams[0]["is_web_public"])
+        self.assertIsNone(never_subscribed_streams[0]["stream_weekly_traffic"])
 
     def test_nonsubscriber(self) -> None:
         """