Professional trading does not exclude chasing gains and cutting losses; it only excludes chasing gains and cutting losses without validation.

Many people's understanding of "chasing gains and cutting losses"
stays at the impulsive following after significant price fluctuations.

But from the perspective of professional traders,
this definition is too crude.

The truly worthwhile chasing gains,
is not because the price has already risen,
but because the market has made an effective breakout at a key level,
and has begun to enter a new trading and pricing zone.

The truly worthwhile cutting losses,
is not because the price has already fallen,
but because the original support logic has failed,
the rebound cannot be repaired,
and the downward trend begins to have a higher probability of continuation.

Therefore, so-called chasing gains and cutting losses,
if it is merely reacting to price outcomes, usually has no advantage;
if it is based on structural confirmation, volatility expansion, and risk re-pricing,
it is a normal part of trend-following trading.