Lazy Trader AISimple definition
A dark pool is a private exchange (technically called an Alternative Trading System, or ATS) where institutions execute large orders. A dark pool print is the public report that one of those large block trades happened — published after the fact.
Why institutions use dark pools
One reason: market impact.
If a hedge fund needs to sell $500M of a stock, doing it openly on the lit exchange would push the price down before they could fill. Routing through a dark pool lets them execute most of the order without telegraphing intent — which gets them a better fill on average.
Other reasons: cross-fund transfers, ETF creation/redemption, anonymous price discovery for thinly-traded names.
What a print tells you
- Size — by definition, prints are far above retail-sized.
- Direction (sometimes) — when prints clear above bid (more aggressive buy) vs. below offer (more aggressive sell), there's a directional read.
- Cluster pattern — repeated prints in the same direction over days can suggest accumulation or distribution.
- Confirmation — when prints align with options flow on the same ticker, the combined signal is stronger.
What a print doesn't tell you
- You can't see the buyer or seller.
- Many prints are mechanical: index rebalances, ETF creations, fund-to-fund transfers.
- The print may have been a hedge for a larger derivative position you can't see.
- Reporting can be delayed by minutes — you're looking at history, not live order flow.
Combining prints with price action
The useful retail playbook isn't “follow every print.” It's:
- Notice when prints cluster in one direction.
- Compare to the ticker's 30-day baseline print size.
- Cross-reference with options flow and price action.
- Watch for prints during earnings windows, M&A windows, or after major news.
How Lazy Trader AI surfaces dark pool context
We ingest the consolidated tape, score every print against its 30-day baseline, tag buy-side / sell-side leaning where possible, and ship it as an alert with an AI summary in plain English.