MASI Dark Pool Activity
ATS off-exchange volume intelligence · Week of 2026-06-08
MASI dark pool volume for the week of 2026-06-08: 1.0M shares traded across 23 ATS venues with a total notional value of $181.9M. Volume is up 0.7% week-over-week. Primary routing venues include , INTELLIGENT CROSS LLC, UBS ATS.
Dark pool activity in MASI 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 12-week historical volume and complete venue breakdown for MASI.
Weekly History
| Week | Shares | DP % | WoW |
|---|---|---|---|
| 2026-06-08 | 1.0M | — | +0.7% |
| 2026-06-01 | 1.0M | — | +64.4% |
| 2026-05-25 | 610.5K | — | -30.9% |
| 2026-05-18 | 882.9K | — | -0.1% |
| 2026-05-11 | 883.3K | — | -37.9% |
| 2026-05-04 | 1.4M | — | +173.7% |
| 2026-04-27 | 519.8K | — | — |
| 2026-03-23 | 1.6M | — | -47.5% |
| 2026-03-16 | 3.0M | — | +83.9% |
| 2026-03-09 | 1.6M | — | -5.2% |
| 2026-03-02 | 1.7M | — | -37.4% |
| 2026-02-23 | 2.7M | — | -67.9% |