What it means
Crowded shorts plus a surprise rally is the classic recipe.
In practice
A squeeze feeds on itself: rising prices force short sellers to buy back, their buying lifts price further, and that hits the next group of stops. Traders spot the conditions by looking for heavy short interest in stocks or very negative funding in crypto.
On a chart the fuel sits above obvious highs, where the shorts' buy stops are clustered. A break of those highs with rising volume is often the start.
What to watch for
Squeeze moves are fast and end abruptly once the forced buying is done. Buying late in one is risky, and shorting it early because the price makes no sense is worse.