diff --git a/piker/ui/_chart.py b/piker/ui/_chart.py
index dd713a04..780262fc 100644
--- a/piker/ui/_chart.py
+++ b/piker/ui/_chart.py
@@ -276,6 +276,8 @@ class ChartnPane(QFrame):
         hbox.setContentsMargins(0, 0, 0, 0)
         hbox.setSpacing(3)
 
+        # self.setMaximumWidth()
+
 
 class LinkedSplits(QWidget):
     '''
@@ -339,7 +341,8 @@ class LinkedSplits(QWidget):
 
     def set_split_sizes(
         self,
-        prop: float = 0.375  # proportion allocated to consumer subcharts
+        # prop: float = 0.375,  # proportion allocated to consumer subcharts
+        prop: float = 5/8,
 
     ) -> None:
         '''Set the proportion of space allocated for linked subcharts.
@@ -450,7 +453,6 @@ class LinkedSplits(QWidget):
             self.xaxis = xaxis
 
         qframe = ChartnPane(sidepane=sidepane, parent=self.splitter)
-
         cpw = ChartPlotWidget(
 
             # this name will be used to register the primary
@@ -522,10 +524,10 @@ class LinkedSplits(QWidget):
             # track by name
             self.subplots[name] = cpw
 
-            if sidepane:
-                # TODO: use a "panes" collection to manage this?
-                sidepane.setMinimumWidth(self.chart.sidepane.width())
-                sidepane.setMaximumWidth(self.chart.sidepane.width())
+            # if sidepane:
+            #     # TODO: use a "panes" collection to manage this?
+            #     qframe.setMaximumWidth(self.chart.sidepane.width())
+            #     qframe.setMinimumWidth(self.chart.sidepane.width())
 
             self.splitter.addWidget(qframe)
 
@@ -537,6 +539,16 @@ class LinkedSplits(QWidget):
 
         return cpw
 
+    def resize_sidepanes(
+        self,
+    ) -> None:
+        '''Size all sidepanes based on the OHLC "main" plot.
+
+        '''
+        for name, cpw in self.subplots.items():
+            cpw.sidepane.setMinimumWidth(self.chart.sidepane.width())
+            cpw.sidepane.setMaximumWidth(self.chart.sidepane.width())
+
 
 class ChartPlotWidget(pg.PlotWidget):
     '''
@@ -681,9 +693,9 @@ class ChartPlotWidget(pg.PlotWidget):
         """Return a range tuple for the bars present in view.
         """
         l, r = self.view_range()
-        a = self._arrays['ohlc']
-        lbar = max(l, a[0]['index'])
-        rbar = min(r, a[-1]['index'])
+        array = self._arrays['ohlc']
+        lbar = max(l, array[0]['index'])
+        rbar = min(r, array[-1]['index'])
         return l, lbar, rbar, r
 
     def default_view(
@@ -991,22 +1003,19 @@ class ChartPlotWidget(pg.PlotWidget):
             a = self._arrays['ohlc']
             ifirst = a[0]['index']
             bars = a[lbar - ifirst:rbar - ifirst + 1]
-
             if not len(bars):
                 # likely no data loaded yet or extreme scrolling?
                 log.error(f"WTF bars_range = {lbar}:{rbar}")
                 return
 
-            # TODO: should probably just have some kinda attr mark
-            # that determines this behavior based on array type
-            try:
+            if self.data_key != self.linked.symbol.key:
+                bars = a[self.data_key]
+                ylow = np.nanmin(bars)
+                yhigh = np.nanmax((bars))
+            else:
+                # just the std ohlc bars
                 ylow = np.nanmin(bars['low'])
                 yhigh = np.nanmax(bars['high'])
-            except (IndexError, ValueError):
-                # likely non-ohlc array?
-                bars = bars[self.name]
-                ylow = np.nanmin(bars)
-                yhigh = np.nanmax(bars)
 
         if set_range:
             # view margins: stay within a % of the "true range"
diff --git a/piker/ui/_display.py b/piker/ui/_display.py
index dcc04f47..254fee76 100644
--- a/piker/ui/_display.py
+++ b/piker/ui/_display.py
@@ -18,6 +18,7 @@
 Real-time display tasks for charting / graphics.
 
 '''
+from contextlib import asynccontextmanager
 import time
 from typing import Any
 from types import ModuleType
@@ -264,7 +265,7 @@ async def chart_from_quotes(
                 last_mx, last_mn = mx, mn
 
 
-async def spawn_fsps(
+async def fan_out_spawn_fsp_daemons(
 
     linkedsplits: LinkedSplits,
     fsps: dict[str, str],
@@ -275,109 +276,93 @@ async def spawn_fsps(
     loglevel: str,
 
 ) -> None:
-    """Start financial signal processing in subactor.
+    '''Create financial signal processing sub-actors (under flat tree)
+    for each entry in config and attach to local graphics update tasks.
 
     Pass target entrypoint and historical data.
 
-    """
-
+    '''
     linkedsplits.focus()
 
     uid = tractor.current_actor().uid
 
     # spawns sub-processes which execute cpu bound FSP code
-    async with tractor.open_nursery(loglevel=loglevel) as n:
+    async with (
+        tractor.open_nursery() as n,
+        trio.open_nursery() as ln,
+    ):
 
-        # spawns local task that consume and chart data streams from
-        # sub-procs
-        async with trio.open_nursery() as ln:
+        # Currently we spawn an actor per fsp chain but
+        # likely we'll want to pool them eventually to
+        # scale horizonatlly once cores are used up.
+        for display_name, conf in fsps.items():
 
-            # Currently we spawn an actor per fsp chain but
-            # likely we'll want to pool them eventually to
-            # scale horizonatlly once cores are used up.
-            for display_name, conf in fsps.items():
+            fsp_func_name = conf['fsp_func_name']
 
-                fsp_func_name = conf['fsp_func_name']
+            # TODO: load function here and introspect
+            # return stream type(s)
 
-                # TODO: load function here and introspect
-                # return stream type(s)
+            # TODO: should `index` be a required internal field?
+            fsp_dtype = np.dtype([('index', int), (fsp_func_name, float)])
 
-                # TODO: should `index` be a required internal field?
-                fsp_dtype = np.dtype([('index', int), (fsp_func_name, float)])
+            key = f'{sym}.fsp.{display_name}.{".".join(uid)}'
 
-                key = f'{sym}.fsp.{display_name}.{".".join(uid)}'
+            # this is all sync currently
+            shm, opened = maybe_open_shm_array(
+                key,
+                # TODO: create entry for each time frame
+                dtype=fsp_dtype,
+                readonly=True,
+            )
 
-                # this is all sync currently
-                shm, opened = maybe_open_shm_array(
-                    key,
-                    # TODO: create entry for each time frame
-                    dtype=fsp_dtype,
-                    readonly=True,
-                )
+            # XXX: fsp may have been opened by a duplicate chart.
+            # Error for now until we figure out how to wrap fsps as
+            # "feeds".  assert opened, f"A chart for {key} likely
+            # already exists?"
 
-                # XXX: fsp may have been opened by a duplicate chart.
-                # Error for now until we figure out how to wrap fsps as
-                # "feeds".  assert opened, f"A chart for {key} likely
-                # already exists?"
+            conf['shm'] = shm
 
-                conf['shm'] = shm
+            portal = await n.start_actor(
+                enable_modules=['piker.fsp'],
+                name='fsp.' + display_name,
+            )
 
-                portal = await n.start_actor(
-                    enable_modules=['piker.fsp'],
-                    name='fsp.' + display_name,
-                )
+            # init async
+            ln.start_soon(
+                run_fsp,
+                portal,
+                linkedsplits,
+                brokermod,
+                sym,
+                src_shm,
+                fsp_func_name,
+                display_name,
+                conf,
+                group_status_key,
+                loglevel,
+            )
 
-                # init async
-                ln.start_soon(
-                    run_fsp,
-                    portal,
-                    linkedsplits,
-                    brokermod,
-                    sym,
-                    src_shm,
-                    fsp_func_name,
-                    display_name,
-                    conf,
-                    group_status_key,
-                )
-
-        # blocks here until all fsp actors complete
+    # blocks here until all fsp actors complete
 
 
-async def run_fsp(
+class FspConfig(BaseModel):
+    class Config:
+        validate_assignment = True
 
-    portal: tractor._portal.Portal,
-    linkedsplits: LinkedSplits,
-    brokermod: ModuleType,
-    sym: str,
-    src_shm: ShmArray,
-    fsp_func_name: str,
+    name: str
+    period: int
+
+
+@asynccontextmanager
+async def open_sidepane(
+
+    linked: LinkedSplits,
     display_name: str,
-    conf: dict[str, Any],
-    group_status_key: str,
 
-) -> None:
-    """FSP stream chart update loop.
-
-    This is called once for each entry in the fsp
-    config map.
-    """
-    done = linkedsplits.window().status_bar.open_status(
-        f'loading fsp, {display_name}..',
-        group_key=group_status_key,
-    )
-
-    # make sidepane config widget
-    class FspConfig(BaseModel):
-
-        class Config:
-            validate_assignment = True
-
-        name: str
-        period: int
+) -> FspConfig:
 
     sidepane: FieldsForm = mk_form(
-        parent=linkedsplits.godwidget,
+        parent=linked.godwidget,
         fields_schema={
             'name': {
                 'label': '**fsp**:',
@@ -386,6 +371,8 @@ async def run_fsp(
                     f'{display_name}'
                 ],
             },
+
+            # TODO: generate this from input map
             'period': {
                 'label': '**period**:',
                 'type': 'edit',
@@ -403,10 +390,46 @@ async def run_fsp(
         print(f'{key}: {value}')
         return True
 
+    # TODO:
+    async with (
+        open_form_input_handling(
+            sidepane,
+            focus_next=linked.godwidget,
+            on_value_change=settings_change,
+        )
+    ):
+        yield sidepane
+
+
+async def run_fsp(
+
+    portal: tractor._portal.Portal,
+    linkedsplits: LinkedSplits,
+    brokermod: ModuleType,
+    sym: str,
+    src_shm: ShmArray,
+    fsp_func_name: str,
+    display_name: str,
+    conf: dict[str, Any],
+    group_status_key: str,
+    loglevel: str,
+
+) -> None:
+    '''FSP stream chart update loop.
+
+    This is called once for each entry in the fsp
+    config map.
+
+    '''
+    done = linkedsplits.window().status_bar.open_status(
+        f'loading fsp, {display_name}..',
+        group_key=group_status_key,
+    )
+
     async with (
         portal.open_stream_from(
 
-            # subactor entrypoint
+            # chaining entrypoint
             fsp.cascade,
 
             # name as title of sub-chart
@@ -415,15 +438,14 @@ async def run_fsp(
             dst_shm_token=conf['shm'].token,
             symbol=sym,
             fsp_func_name=fsp_func_name,
+            loglevel=loglevel,
 
         ) as stream,
 
-        # TODO:
-        open_form_input_handling(
-            sidepane,
-            focus_next=linkedsplits.godwidget,
-            on_value_change=settings_change,
-        ),
+        open_sidepane(
+            linkedsplits,
+            display_name,
+        ) as sidepane,
     ):
 
         # receive last index for processed historical
@@ -472,7 +494,7 @@ async def run_fsp(
             # read from last calculated value
             array = shm.array
 
-            # XXX: fsp func names are unique meaning we don't have
+            # XXX: fsp func names must be unique meaning we don't have
             # duplicates of the underlying data even if multiple
             # sub-charts reference it under different 'named charts'.
             value = array[fsp_func_name][-1]
@@ -489,6 +511,8 @@ async def run_fsp(
             array_key=fsp_func_name
         )
 
+        chart.linked.resize_sidepanes()
+
         # TODO: figure out if we can roll our own `FillToThreshold` to
         # get brush filled polygons for OS/OB conditions.
         # ``pg.FillBetweenItems`` seems to be one technique using
@@ -622,6 +646,73 @@ async def check_for_new_bars(feed, ohlcv, linkedsplits):
             price_chart.increment_view()
 
 
+def has_vlm(ohlcv: ShmArray) -> bool:
+    # make sure that the instrument supports volume history
+    # (sometimes this is not the case for some commodities and
+    # derivatives)
+    volm = ohlcv.array['volume']
+    return not bool(np.all(np.isin(volm, -1)) or np.all(np.isnan(volm)))
+
+
+@asynccontextmanager
+async def maybe_open_vlm_display(
+
+    linked: LinkedSplits,
+    ohlcv: ShmArray,
+
+) -> ChartPlotWidget:
+
+    # make sure that the instrument supports volume history
+    # (sometimes this is not the case for some commodities and
+    # derivatives)
+    # volm = ohlcv.array['volume']
+    # if (
+    #     np.all(np.isin(volm, -1)) or
+    #     np.all(np.isnan(volm))
+    # ):
+    if not has_vlm(ohlcv):
+        log.warning(f"{linked.symbol.key} does not seem to have volume info")
+    else:
+        async with open_sidepane(linked, 'volume') as sidepane:
+            # built-in $vlm
+            shm = ohlcv
+            chart = linked.add_plot(
+                name='vlm',
+                array=shm.array,
+
+                array_key='volume',
+                sidepane=sidepane,
+
+                # curve by default
+                ohlc=False,
+
+                # vertical bars
+                # stepMode=True,
+                # static_yrange=(0, 100),
+            )
+
+            # XXX: ONLY for sub-chart fsps, overlays have their
+            # data looked up from the chart's internal array set.
+            # TODO: we must get a data view api going STAT!!
+            chart._shm = shm
+
+            # should **not** be the same sub-chart widget
+            assert chart.name != linked.chart.name
+
+            # sticky only on sub-charts atm
+            last_val_sticky = chart._ysticks[chart.name]
+
+            # read from last calculated value
+            value = shm.array['volume'][-1]
+
+            last_val_sticky.update_from_data(-1, value)
+
+            # size view to data once at outset
+            chart._set_yrange()
+
+            yield chart
+
+
 async def display_symbol_data(
 
     godwidget: GodWidget,
@@ -686,6 +777,7 @@ async def display_symbol_data(
         # add as next-to-y-axis singleton pane
         godwidget.pp_pane = pp_pane
 
+        # create main OHLC chart
         chart = linkedsplits.plot_ohlc_main(
             symbol,
             bars,
@@ -722,7 +814,7 @@ async def display_symbol_data(
                     'static_yrange': (0, 100),
                 },
             },
-            # test for duplicate fsps on same chart
+            # # test for duplicate fsps on same chart
             # 'rsi2': {
             #     'fsp_func_name': 'rsi',
             #     'period': 14,
@@ -733,18 +825,8 @@ async def display_symbol_data(
 
         }
 
-        # make sure that the instrument supports volume history
-        # (sometimes this is not the case for some commodities and
-        # derivatives)
-        volm = ohlcv.array['volume']
-        if (
-            np.all(np.isin(volm, -1)) or
-            np.all(np.isnan(volm))
-        ):
-            log.warning(
-                f"{sym} does not seem to have volume info,"
-                " dropping volume signals")
-        else:
+        if has_vlm(ohlcv):
+            # add VWAP to fsp config for downstream loading
             fsp_conf.update({
                 'vwap': {
                     'fsp_func_name': 'vwap',
@@ -756,11 +838,10 @@ async def display_symbol_data(
         async with (
 
             trio.open_nursery() as ln,
-
         ):
             # load initial fsp chain (otherwise known as "indicators")
             ln.start_soon(
-                spawn_fsps,
+                fan_out_spawn_fsp_daemons,
                 linkedsplits,
                 fsp_conf,
                 sym,
@@ -787,6 +868,7 @@ async def display_symbol_data(
             )
 
             async with (
+                maybe_open_vlm_display(linkedsplits, ohlcv),
 
                 open_order_mode(
                     feed,