It is the opposite of the Destructive Volatility. The stock is resting, not breaking down.
Before the coil, the stock has usually already shown strength through an advance, breakout, or strong recovery. This is NVDA before a 90% or ~170% (if you did not sell a pullback) leg.

During the coiled-spring phase, you typically observe:
price moves sideways or slightly upward
price still spends time near the upper part of its recent range
selling attempts produce less downside progress
important support and moving averages hold
price repeatedly approaches resistance without suffering a major rejection
volume often declines as the range tightens
Moving averages compress but remain positive
RS remains green or neutral. No sustained periods of weak RS.
Volatility regime remains low or normal.