An order block is the last opposite-coloured candle before a strong directional move. SMC traders treat these candles as institutional footprints — the places where large orders absorbed the previous direction and reversed price. The theory says price often returns to these zones and reacts from them.
There are two variants: bullish (a red candle followed by a strong up-move) and bearish (a green candle followed by a strong down-move). Both follow the same mechanic, mirrored.
A bullish order block is the last red (down) candle before a strong upward move. The narrative: institutions absorbed selling at this candle and reversed the market. The zone is typically marked from the open to the close of the order block candle — sometimes extended to include the wicks. When price returns to this zone, the theory says buyers should step in again and the level holds as support.
A bearish order block is the mirror. The last green (up) candle before a strong downward move. The zone acts as resistance when revisited — institutions are theorised to be sitting on offers at this level, ready to defend it.
The narrative claim: an order block is where institutional orders accumulated before the move began. The theory says some of these orders are not all filled at once — remaining size sits unfilled at the level, ready to be triggered if price returns. The level therefore has structural significance and traders watch for reactions when price revisits it.
The skeptical view: order blocks are easily identified in retrospect, but predicting which candles will act as support or resistance in advance is much harder. Many candles look like potential order blocks at the time; only some end up holding when revisited. The retrospective clarity is a survivorship-bias trap.
The honest position: order blocks at major structural levels, in the direction of a higher-timeframe trend, with confluence from other tools (FVGs, prior highs/lows, session opens) are more likely to act as expected than random order blocks marked in chop. Filtering matters more than the concept itself.
Key insight: Not every opposite-coloured candle before a move is a useful order block. The ones that hold on retest tend to share three features: they are at a clearly defined structural level, the impulse off them was strong and unambiguous, and the retest happens with the higher-timeframe trend rather than against it. Marking every candle as an OB and trading them indiscriminately is the fastest way to have no edge at all.
The other half is what’s happening in your head when you’re in the trade. Fear, ego, revenge trading, breaking your own stops — that’s where most accounts actually lose money. Not bad setups.