Footprint chart
A chart showing buy (ask) and sell (bid) volume by price level inside each candle, so you can read the "inside" of the candle.
A footprint shows at which levels of the candle aggressive buyers/sellers were active, where volume piled up (high volume nodes) and where imbalances sit (one side at 3 times the other).
Typical reads: price not falling despite selling pressure at the low (absorption), buying volume at the high failing to push price further (exhaustion). It requires real volume → futures.