What is order block?

In financial trading (particularly within Smart Money Concepts and Price Action), an order block refers to a specific candle or cluster of candles representing institutional buying or selling activity before a strong impulsive price move.

​When large financial institutions (banks, hedge funds) want to execute massive orders without crashing or spiking the market, they often need to accumulate or distribute positions in steps. The trace they leave behind creates an order block, which traders look to use as high-probability support or resistance zones when the price returns later.