ALNY Market Structure
Alnylam Pharmaceuticals, Inc. (ALNY) operates in the Healthcare sector, specifically the Biotechnology industry, with a market capitalization near $38.92B, listed on NASDAQ, employing roughly 2,230 people, carrying a beta of 0.30 to the broader market. Alnylam Pharmaceuticals, Inc. Led by Yvonne L. Greenstreet, public since 2004-06-01.
Market structure data reveals where a stock trades across exchanges, dark pools, and alternative trading systems. Understanding off-exchange activity helps identify institutional trading patterns and liquidity dynamics.
- Latest Week Ending
- 2026-04-20
- Weekly OTC Shares
- 703.6K
- Weekly OTC Trades
- 14.8K
- 12-Week Total Shares
- 8.8M
- Avg Trade Size (12-Week)
- 51 shares
How Single-Name Off-Exchange Volume Affects Options
For single-name equities, persistent off-exchange volume concentrations can flag institutional positioning - large blocks arranged through ATS venues to avoid lit-market impact, or correlation-arbitrage flow from sector rotation. The flow doesn't directly move the lit-market price (it prints at the ATS) but it changes the inventory position of the institutional counterparty, which then drives subsequent lit-market flow. Compare the off-exchange volume series above with ALNY's gamma exposure and options volume history to see whether unusual dark-pool activity coincides with rebalancing in the options book.
Showing 12 weeks of off-exchange trading data for Alnylam Pharmaceuticals, Inc..
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Frequently asked ALNY market structure questions
- What is the current ALNY off-exchange volume?
- For the week ending Apr 20, 2026, Alnylam Pharmaceuticals, Inc. (ALNY) recorded 703.6K shares across 14.8K trades (average trade size 47 shares). The 12-week cumulative total is 8.8M shares.
- What does ALNY off-exchange volume mean for traders?
- Off-exchange volume on a single-name equity reflects institutional block trades arranged through alternative trading systems (ATS) for liquidity rather than information reasons. Persistent ATS volume on a name can signal large institutional repositioning; the lit-market price impact lags the off-exchange print by hours to days as the institutional counterparty hedges or unwinds.
- How is ALNY market-structure data sourced?
- Weekly off-exchange volume figures come from FINRA's OTC Transparency reporting, which captures trades executed through FINRA-member off-exchange venues including ATSs and member firm internalization desks. FINRA publishes the data with a two-week lag (current-week-minus-two-weeks) for ATS-specific volume and weekly aggregate volume; the totals here aggregate all member firm reporting. Trades cleared via the listed-exchange auction are NOT included; the figure reflects only the off-exchange portion of total volume.