diff --git a/server/src/sync.test.ts b/server/src/sync.test.ts
index 582e1b6..9ba4da9 100644
--- a/server/src/sync.test.ts
+++ b/server/src/sync.test.ts
@@ -48,6 +48,15 @@ test("fullSync is single-flight", async () => {
   assert.equal(calls, 1);
 });
 
+test("account cursor persists on flush, not per frame", () => {
+  const db = openDb(":memory:");
+  const syncer = new Syncer(db, { hostname: "pds.test" } as unknown as PdsClient, [], stubLogger);
+  (syncer as any).accountCursor = 99;
+  assert.equal(getSyncState(db, "account_stream_cursor"), null);
+  (syncer as any).flushCursor();
+  assert.equal(getSyncState(db, "account_stream_cursor"), "99");
+});
+
 test("account stream url resumes from the persisted cursor", () => {
   const db = openDb(":memory:");
   assert.equal(
diff --git a/server/src/sync.ts b/server/src/sync.ts
index 23ed2d4..90fa821 100644
--- a/server/src/sync.ts
+++ b/server/src/sync.ts
@@ -99,6 +99,8 @@ export class Syncer {
   private stopped = false;
   private syncing = false;
   private timers: NodeJS.Timeout[] = [];
+  // latest firehose seq, persisted on the flush tick — a write per frame would hammer SQLite
+  private accountCursor: number | null = null;
 
   constructor(
     private db: Db,
@@ -131,6 +133,7 @@ export class Syncer {
       void this.flushDirty().catch((err) => this.log.error({ err }, "dirty flush failed"));
       try {
         this.flushActivity();
+        this.flushCursor();
       } catch (err) {
         this.log.error({ err }, "activity flush failed");
       }
@@ -142,13 +145,19 @@ export class Syncer {
     for (const labeler of this.labelers) this.connectLabelStream(labeler);
   }
 
-  /** Shutdown seam: stop reconnects, tear down sockets, cancel timers. */
+  /** Shutdown seam: stop reconnects, tear down sockets, cancel timers, flush buffers. */
   stop() {
     this.stopped = true;
     for (const t of this.timers) clearInterval(t);
     this.timers = [];
     for (const ws of this.sockets) ws.terminate();
     this.sockets = [];
+    try {
+      this.flushActivity();
+      this.flushCursor();
+    } catch (err) {
+      this.log.error({ err }, "final flush failed");
+    }
   }
 
   // ---- full reconcile ------------------------------------------------------
@@ -293,9 +302,7 @@ export class Syncer {
     ws.on("message", (data: Buffer) => {
       try {
         const { header, body } = readFrame(data);
-        if (typeof body?.seq === "number") {
-          setSyncState(this.db, ACCOUNT_STREAM_CURSOR_KEY, String(body.seq));
-        }
+        if (typeof body?.seq === "number") this.accountCursor = body.seq;
         const did: string | undefined = body?.did ?? body?.repo;
         if (!did) return;
         // #account carries active/status directly; #identity means handle changed;
@@ -304,8 +311,12 @@ export class Syncer {
           this.dirty.add(did);
         }
         if (header?.t === "#commit") {
-          // UTC hour buckets; the stats API regroups them into viewer-local days
-          const key = `${new Date().toISOString().slice(0, 13)}|${did}`;
+          // UTC hour buckets; the stats API regroups them into viewer-local days.
+          // Bucket by the event's own time so cursor-replayed backfill after downtime
+          // lands in the hours it happened, not in a spike at reconnect.
+          const eventTime = body.time ? new Date(body.time) : new Date();
+          const at = Number.isNaN(eventTime.getTime()) ? new Date() : eventTime;
+          const key = `${at.toISOString().slice(0, 13)}|${did}`;
           this.activity.set(key, (this.activity.get(key) ?? 0) + 1);
         }
       } catch {
@@ -402,6 +413,12 @@ export class Syncer {
     this.activity.clear();
   }
 
+  private flushCursor() {
+    if (this.accountCursor == null) return;
+    setSyncState(this.db, ACCOUNT_STREAM_CURSOR_KEY, String(this.accountCursor));
+    this.accountCursor = null;
+  }
+
   // ---- live label streams --------------------------------------------------
 
   private connectLabelStream(labeler: WatchedLabeler) {