diff --git a/piker/data/feed.py b/piker/data/feed.py
index e6f4990e..8cb89d81 100644
--- a/piker/data/feed.py
+++ b/piker/data/feed.py
@@ -22,6 +22,7 @@ This module is enabled for ``brokerd`` daemons.
 """
 from __future__ import annotations
 from dataclasses import dataclass, field
+from datetime import datetime
 from contextlib import asynccontextmanager
 from functools import partial
 from types import ModuleType
@@ -31,6 +32,7 @@ from typing import (
     Awaitable,
 )
 
+import pendulum
 import trio
 from trio.abc import ReceiveChannel
 from trio_typing import TaskStatus
@@ -59,6 +61,7 @@ from ._source import (
 from ..ui import _search
 from ._sampling import (
     sampler,
+    broadcast,
     increment_ohlc_buffer,
     iter_ohlc_periods,
     sample_and_broadcast,
@@ -250,6 +253,8 @@ async def manage_history(
 
     open_history_client = getattr(mod, 'open_history_client', None)
 
+    bfqsn = fqsn.replace('.' + mod.name, '')
+
     if is_up and opened and open_history_client:
 
         log.info('Found existing `marketstored`')
@@ -281,45 +286,69 @@ async def manage_history(
                     array,
                     start_dt,
                     end_dt,
+                    last_tsdb_dt: Optional[datetime] = None
 
                 ) -> np.ndarray:
 
-                    s_diff = (last_tsdb_dt - start_dt).seconds
+                    if last_tsdb_dt:
+                        s_diff = (last_tsdb_dt - start_dt).seconds
 
-                    # if we detect a partial frame's worth of data
-                    # that is new, slice out only that history and
-                    # write to shm.
-                    if s_diff > 0:
-                        assert last_tsdb_dt > start_dt
-                        selected = array['time'] > last_tsdb_dt.timestamp()
-                        to_push = array[selected]
-                        log.info(
-                            f'Pushing partial frame {to_push.size} to shm'
-                        )
-                        return to_push
+                        # if we detect a partial frame's worth of data
+                        # that is new, slice out only that history and
+                        # write to shm.
+                        if s_diff > 0:
+                            assert last_tsdb_dt > start_dt
+                            selected = array['time'] > last_tsdb_dt.timestamp()
+                            to_push = array[selected]
+                            log.info(
+                                f'Pushing partial frame {to_push.size} to shm'
+                            )
+                            return to_push
 
-                    else:
-                        return array
+                    return array
 
                 # start history anal and load missing new data via backend.
-                async with open_history_client(fqsn) as hist:
+
+                broker, symbol, expiry = unpack_fqsn(fqsn)
+
+                async with open_history_client(bfqsn) as hist:
 
                     # get latest query's worth of history all the way
                     # back to what is recorded in the tsdb
-                    array, start_dt, end_dt = await hist(end_dt='')
-                    to_push = diff_history(array, start_dt, end_dt)
+                    array, start_dt, end_dt = await hist(end_dt=None)
+                    to_push = diff_history(
+                        array,
+                        start_dt,
+                        end_dt,
+                        last_tsdb_dt=last_tsdb_dt,
+                    )
+                    log.info(f'Pushing {to_push.size} to shm!')
                     shm.push(to_push)
 
+                    for delay_s in sampler.subscribers:
+                        await broadcast(delay_s)
+
                     # let caller unblock and deliver latest history frame
                     task_status.started(shm)
                     some_data_ready.set()
 
                     # pull new history frames until we hit latest
                     # already in the tsdb
-                    while start_dt > last_tsdb_dt:
+                    # while start_dt > last_tsdb_dt:
+                    while True:
                         array, start_dt, end_dt = await hist(end_dt=start_dt)
-                        to_push = diff_history(array, start_dt, end_dt)
+                        to_push = diff_history(
+                            array,
+                            start_dt,
+                            end_dt,
+                            # last_tsdb_dt=last_tsdb_dt,
+                            # just run indefinitely
+                            last_tsdb_dt=None,
+                        )
+                        log.info(f'Pushing {to_push.size} to shm!')
                         shm.push(to_push, prepend=True)
+                        for delay_s in sampler.subscribers:
+                            await broadcast(delay_s)
 
                     # TODO: see if there's faster multi-field reads:
                     # https://numpy.org/doc/stable/user/basics.rec.html#accessing-multiple-fields
@@ -348,7 +377,6 @@ async def manage_history(
         # do a legacy incremental backfill from the provider.
         log.info('No existing `marketstored` found..')
 
-        bfqsn = fqsn.replace('.' + mod.name, '')
         # start history backfill task ``backfill_bars()`` is
         # a required backend func this must block until shm is
         # filled with first set of ohlc bars