CSA Dark Pool Activity

ATS off-exchange volume intelligence · Week of 2025-04-21

CSA dark pool volume for the week of 2025-04-21: 808 shares traded across 5 ATS venues with a total notional value of $53K. Volume is up 75.7% week-over-week. Primary routing venues include , VIRTU MATCHIT ATS, SIGMA X2.

Dark pool activity in CSA reflects institutional order flow executing on Alternative Trading Systems (ATS) registered with the SEC — private venues where large-block trades are matched away from public exchanges to minimize price impact. StonkWhisper ingests FINRA-published ATS volume data to track these off-exchange flows. Sustained elevation in dark pool percentage — particularly when concentrated at specific venues — can indicate institutional accumulation or distribution ahead of significant price moves. The interactive charts below show 7-week historical volume and complete venue breakdown for CSA.