What Is Gap Fill?
A gap fill occurs when price returns to and trades through a price zone where a gap previously existed. In crypto, the most relevant gaps are CME Bitcoin futures gaps — the price difference between Friday's close and Monday's open. These gaps fill approximately 90% of the time, though the timing can range from hours to months.
How Gap Fill Works
Gap fills work because they represent areas of inefficient price discovery — no trading occurred at those prices, so there are no natural support/resistance levels within the gap. Price tends to "discover" these prices eventually. The magnetic pull of unfilled gaps creates a probabilistic framework: price has a statistically significant tendency to revisit these zones.
Why It Matters for Traders
CME gap fills are among the most reliable setups in crypto. Traders track unfilled CME gaps as price targets: if there's an unfilled gap below the current price, it creates a bearish target; above, a bullish target. The strategy works best when combined with other technical factors — a gap fill at a key support level with RSI divergence is particularly powerful.