Fair Value Gap Finder
Boxes the holes fast candles leave behind, and tracks whether they get filled.
When three candles leave a gap between the first candle's high and the third's low (or the reverse), this draws it as a box. Boxes shrink as price trades back into them and are removed, or greyed out, once filled. You can hide small gaps, show only gaps matching the trend, and keep filled gaps to see how often they really do fill.