diff --git a/piker/ui/_display.py b/piker/ui/_display.py
index c2333350..df51d444 100644
--- a/piker/ui/_display.py
+++ b/piker/ui/_display.py
@@ -106,7 +106,7 @@ def chart_maxmin(
     return last_bars_range, mx, max(mn, 0), mx_vlm_in_view
 
 
-async def update_linked_charts_graphics(
+async def graphics_update_loop(
     linked: LinkedSplits,
     stream: tractor.MsgStream,
     ohlcv: np.ndarray,
@@ -258,13 +258,15 @@ async def update_linked_charts_graphics(
                     )
                     last_mx_vlm = mx_vlm_in_view
 
-                for curve_name, shm in vlm_chart._overlays.items():
+                for curve_name, flow in vlm_chart._flows.items():
                     update_fsp_chart(
                         vlm_chart,
-                        shm,
+                        flow.shm,
                         curve_name,
                         array_key=curve_name,
                     )
+                    # is this even doing anything?
+                    flow.plot.vb._set_yrange()
 
             ticks_frame = quote.get('ticks', ())
 
@@ -411,14 +413,14 @@ async def update_linked_charts_graphics(
                 # TODO: all overlays on all subplots..
 
             # run synchronous update on all derived overlays
-            for curve_name, shm in chart._overlays.items():
+            for curve_name, flow in chart._flows.items():
                 update_fsp_chart(
                     chart,
-                    shm,
+                    flow.shm,
                     curve_name,
                     array_key=curve_name,
                 )
-                # chart._set_yrange()
+                # chart.view._set_yrange()
 
 
 async def check_for_new_bars(
@@ -473,11 +475,11 @@ async def check_for_new_bars(
             )
 
             # main chart overlays
-            for name in price_chart._overlays:
-
+            # for name in price_chart._flows:
+            for curve_name in price_chart._flows:
                 price_chart.update_curve_from_array(
-                    name,
-                    price_chart._arrays[name]
+                    curve_name,
+                    price_chart._arrays[curve_name]
                 )
 
             # each subplot
@@ -614,7 +616,7 @@ async def display_symbol_data(
 
             # start graphics update loop after receiving first live quote
             ln.start_soon(
-                update_linked_charts_graphics,
+                graphics_update_loop,
                 linkedsplits,
                 feed.stream,
                 ohlcv,
diff --git a/piker/ui/_fsp.py b/piker/ui/_fsp.py
index bd037d9e..03d483a0 100644
--- a/piker/ui/_fsp.py
+++ b/piker/ui/_fsp.py
@@ -250,7 +250,7 @@ async def run_fsp_ui(
                 **conf.get('chart_kwargs', {})
             )
             # specially store ref to shm for lookup in display loop
-            chart._overlays[name] = shm
+            chart._flows[name].shm = shm
 
         else:
             # create a new sub-chart widget for this fsp
@@ -634,7 +634,9 @@ async def open_vlm_displays(
             for name in names:
                 mxmn = chart.maxmin(name=name)
                 if mxmn:
-                    mx = max(mxmn[1], mx)
+                    ymax = mxmn[1]
+                    if ymax > mx:
+                        mx = ymax
 
             return 0, mx
 
@@ -730,8 +732,8 @@ async def open_vlm_displays(
 
             # all to be overlayed curve names
             fields = [
-                'dolla_vlm',
-                'dark_vlm',
+               'dolla_vlm',
+               'dark_vlm',
             ]
             dvlm_rate_fields = [
                 'dvlm_rate',
@@ -794,7 +796,7 @@ async def open_vlm_displays(
                     # specially store ref to shm for lookup in display loop
                     # since only a placeholder of `None` is entered in
                     # ``.draw_curve()``.
-                    chart._overlays[name] = shm
+                    chart._flows[name].shm = shm
 
             chart_curves(
                 fields,
@@ -857,7 +859,7 @@ async def open_vlm_displays(
 
                 # dashed line to represent "individual trades" being
                 # more "granular" B)
-                # style='dash',
+                style='dash',
             )
 
             for pi in (dvlm_pi, tr_pi):