ICT SIBI and BISI — Sell-Side Imbalance Buy-Side Inefficiency Explained
SIBI and BISI are ICT's terms for specific types of price imbalances that identify one-sided institutional delivery. Understanding them clarifies when an FVG is bullish or bearish at its core.
SIBI and BISI are ICT's specific terminology for the two types of Fair Value Gaps, classified by the institutional imbalance they represent. BISI stands for Buy-Side Imbalance Sell-Side Inefficiency — a bullish FVG. SIBI stands for Sell-Side Imbalance Buy-Side Inefficiency — a bearish FVG. These terms clarify the nature of each FVG: who was imbalanced (dominant), and who was inefficient (absent) during the gap formation.
BISI — Buy-Side Imbalance Sell-Side Inefficiency
A BISI (bullish FVG) forms during a bullish displacement. The "Buy-Side Imbalance" refers to the overwhelming institutional buying that drove price through the gap level — buyers dominated so completely that sellers were entirely absent or inefficient at filling orders within the gap range. The "Sell-Side Inefficiency" means sellers could not participate at those price levels because the buying pressure was too aggressive.
The BISI acts as support on the retracement. When price returns to the BISI zone, the sellers who were previously inefficient are now attempting to sell into the zone — but the institutional buyers who created the BISI are there to absorb that selling and continue the bullish delivery. The BISI is where bulls are aggressive and bears are weak.
SIBI — Sell-Side Imbalance Buy-Side Inefficiency
A SIBI (bearish FVG) forms during a bearish displacement. "Sell-Side Imbalance" refers to institutional selling so dominant that buyers were entirely absent within the gap range. The "Buy-Side Inefficiency" means buyers could not fill orders at those prices during the displacement — they were overwhelmed.
The SIBI acts as resistance on the retracement. When price returns to the SIBI zone, buyers who were previously absent attempt to buy — but the institutional sellers who created the SIBI are positioned to absorb that buying and continue the bearish delivery. The SIBI is where bears are aggressive and bulls are inefficient.
Using SIBI/BISI in Practice
- diamondEvery FVG is either a BISI (bullish, acts as support) or a SIBI (bearish, acts as resistance).
- diamondOnly buy BISI zones in bullish institutional order flow. Only sell SIBI zones in bearish order flow.
- diamondNever buy a SIBI and never sell a BISI — the institutional imbalance is against you.
- diamondWhen a BISI is violated (price trades through it), it may become a SIBI equivalent in the new direction — this is the IFVG (Implied/Inverted FVG) concept.
- diamondMark all FVGs on your chart with their classification: BISI for bullish FVGs (mark in green), SIBI for bearish FVGs (mark in red). This visual distinction immediately tells you which FVGs are tradeable in which direction.
The SIBI/BISI terminology is useful beyond just naming — it reinforces the directional discipline required for FVG trading. By explicitly labeling each FVG as SIBI or BISI, you are forced to confront the question: "Is this FVG in the direction of my bias?" A bullish trader looking at a SIBI must consciously recognize they are looking at bearish institutional imbalance — a reminder not to buy it. This labeling practice reduces counter-trend FVG entries significantly.