The amount of candle-to-candle price overlap. High friction means repeated trading through the same territory; low friction means cleaner directional progress into new territory.
Full Explanation
Friction is a direct visual description of how much candles overlap one another. When candles repeatedly trade through the same price ranges, alternate direction, and revisit prior territory, friction is high. When candles stack cleanly with limited overlap and continue extending into new territory, friction is low.
Mechanically, high friction suggests that aggression is meeting enough opposing liquidity to prevent clean relocation. Neither side is consistently taking new territory without being answered. Low friction suggests one direction of aggression is more consistently overrunning the liquidity available to contain it.
The change in friction is often more informative than the absolute level. A clean move developing more overlap can indicate that the conditions supporting relocation are degrading. A choppy market becoming progressively cleaner can indicate that balance is breaking. Friction is a read of current behavior, not a promise about what price will do next.