diff --git a/piker/data/marketstore.py b/piker/data/marketstore.py
index c84b5a78..fccd13b4 100644
--- a/piker/data/marketstore.py
+++ b/piker/data/marketstore.py
@@ -421,7 +421,7 @@ class Storage:
     async def read_ohlcv(
         self,
         fqsn: str,
-        timeframe: Optional[Union[int, str]] = None,
+        timeframe: int | str,
         end: Optional[int] = None,
         limit: int = int(800e3),
 
@@ -429,11 +429,13 @@ class Storage:
         int,
         Union[dict, np.ndarray],
     ]:
+
         client = self.client
         syms = await client.list_symbols()
 
         if fqsn not in syms:
-            return {}
+            raise KeyError('No entry for {fqsn}')
+            # return {}
 
         # use the provided timeframe or 1s by default
         tfstr = tf_in_1s.get(timeframe, tf_in_1s[1])
@@ -462,17 +464,19 @@ class Storage:
         data_set = result.by_symbols()[fqsn]
         array = data_set.array
 
-        # XXX: market store BUG!
-        # for wtv cucked reason seems like despite the params
-        # timeframe being set to a "lower" value the higher
-        # valued data set will still be pulled?..
+        # XXX: ensure sample rate is as expected
         time = data_set.array['Epoch']
         if len(time) > 1:
-            time_step = time[1] - time[0]
+            time_step = time[-1] - time[-2]
             ts = tf_in_1s.inverse[data_set.timeframe]
-            if time_step > ts:
-                log.warning(f'MKTS BUG: wrong timeframe loaded: {time_step}')
-                return {}
+
+            assert time_step == ts
+
+            # if time_step != ts:
+            #     log.warning(f'MKTS BUG: wrong timeframe loaded: {time_step}')
+            #     if timeframe == 1:
+            #         await tractor.breakpoint()
+            #     return {}
 
         return array
 
@@ -525,17 +529,18 @@ class Storage:
 
         m, r = divmod(len(mkts_array), limit)
 
+        tfkey = tf_in_1s[timeframe]
         for i in range(m, 1):
             to_push = mkts_array[i-1:i*limit]
 
             # write to db
             resp = await self.client.write(
                 to_push,
-                tbk=f'{fqsn}/{tf_in_1s[timeframe]}/OHLCV',
+                tbk=f'{fqsn}/{tfkey}/OHLCV',
 
                 # NOTE: will will append duplicates
                 # for the same timestamp-index.
-                # TODO: pre deduplicate?
+                # TODO: pre-deduplicate?
                 isvariablelength=append_and_duplicate,
             )
 
@@ -554,7 +559,7 @@ class Storage:
             # write to db
             resp = await self.client.write(
                 to_push,
-                tbk=f'{fqsn}/1Sec/OHLCV',
+                tbk=f'{fqsn}/{tfkey}/OHLCV',
 
                 # NOTE: will will append duplicates
                 # for the same timestamp-index.