Why dark pools exist
If a fund showed a 2-million-share buy order on a public exchange, other traders would jump ahead of it and push the price up. Dark pools hide the order until it is done, which lowers that cost. They are legal, regulated venues and handle a large share of U.S. stock volume.
How to read a print
- Size and value: the number of shares and dollar amount. Bigger prints carry more weight.
- Price vs the bid/ask: a print near the ask leans toward buying; near the bid leans toward selling — but this is a hint, not proof.
- Repeated levels: several large prints at the same price can mark a level institutions care about.
What prints cannot tell you
- Direction: every trade has a buyer and a seller. A print does not say who started it.
- Intent: the trade may be a hedge, a rebalance or one leg of a bigger strategy.
- Timing: prints are reported after the fact, sometimes with a short delay.
Ways traders use it (examples, not advice)
- Mark price levels with heavy dark pool volume as possible support or resistance.
- Combine prints with unusual options flow in the same ticker for confirmation.
- Ignore single small prints; look for size and repetition.