Gamma (dealer hedging)
When crowds buy call options and dealers end up net short those options, the dealers buy stock to stay hedged — and the higher the stock goes, the MORE stock they need. That mechanical feedback loop amplifies moves in both directions. Whether it fires at all depends on which side of the options the dealers actually hold.
Dealer hedging of heavy call flow steepens rallies (forced buying into strength) and steepens the unwind (hedges sold as the calls decay or are dumped). Heavily skewed call-to-put flow on short expiries — the 0DTE (zero days to expiry) extreme — is the classic accelerant signature. Two honest cautions: gamma explains SPEED, not direction, and it is regime-dependent — the same flow print means different things at high and low Implied volatility (IV). Never promote "gamma squeeze" to the cause of a move before the positioning and borrow checks have run; it is usually the amplifier, not the engine.