Section 2 · Market Mechanics
Dark Pools
Legal, invisible, and responsible for 40% of all US stock trading.
Dark pools are legal — but invisible to most traders.
About 40% of all US stock trading happens off-exchange. Institutions use dark pools to avoid moving the visible market when executing large orders.
3 things to know
Dark pools are private exchanges — orders are not visible to the public.
Major banks and institutions use dark pools to trade large blocks without alerting the market.
Dark pool trades still appear on Time & Sales after the fact — they just print late.
Dive Deeper
Key vocabulary — tap each card
Practice
Myth
Dark pools are illegal and manipulative.
Myth
Retail traders can use dark pools too.
Did you know?
The term "dark" refers to price opacity, not anything sinister. The largest dark pool is run by JPMorgan Chase. Their private exchange handles more volume per day than some entire countries' stock markets.