Block Trade
A single large transaction — typically 10,000+ shares or $200,000+ in value — usually executed privately to minimize market impact.
A block trade is a large, privately negotiated transaction executed outside the normal order book to avoid moving the market. The threshold varies by venue, but in U.S. equities it is typically 10,000 shares or $200,000 in notional value.
Block trades are arranged through broker upstairs desks or executed in dark pools. Once agreed, they are reported to the tape but often delayed, meaning other participants may not know a large transaction occurred until minutes after the fact.
Watching for block prints on the time and sales — especially at prices away from the prevailing quote — is a common technique for gauging institutional conviction.
Related Terms
Dark Pool
A private, off-exchange trading venue where large institutional orders are matched anonymously without pre-trade transparency.
AdvancedIceberg Order
A large order split so only a small visible portion shows in the order book; the rest is hidden and refreshes automatically as each slice fills.
AdvancedMarket Depth
The volume of open buy and sell orders at various price levels — a measure of how much size the market can absorb without large price movement.
IntermediateMarket Impact
The adverse price movement caused by your own order consuming liquidity — buying pushes price up, selling pushes it down.
AdvancedMarket-on-Open / Market-on-Close (MOO/MOC)
Auction orders that execute at the official opening (MOO) or closing (MOC) price — guaranteeing the auction print but not a specific price.
IntermediateOrder Flow
The stream of incoming buy and sell orders hitting the market — analysis of order flow reveals who is aggressive and where price is likely headed next.
AdvancedSlippage
The difference between the expected fill price and the actual fill price. Positive slippage benefits you; negative slippage costs you.
BeginnerTime and Sales
The chronological record of every executed trade in a security — price, size, and timestamp — also called reading the tape.
Intermediate