Market, limit, stop-market, stop-limit, take-profit, trailing stop and TWAP, with post-only and reduce-only modifiers.
The modifiers matter more than the types
Reduce-only guarantees an order can only shrink a position, never open or flip one. It’s what makes a stop safe — without it, a stop firing on a position you’ve already closed opens a new one in the opposite direction.
Post-only rejects an order that would execute immediately as a taker. It guarantees the maker rate, at the cost of the order sometimes not being placed at all.
Trailing stops
A trailing stop follows price at a set distance and triggers when price retraces by that amount. The weakness: the distance is fixed while volatility isn’t. A trail wide enough to survive a normal session gives back too much in a quiet one; a tight trail gets taken out by noise.
Closing a position
Market-closing works, and on a large position in a thin book it’s expensive. Reduce-only limit orders let you exit at your price, with the risk of not exiting at all.
TWAP
Hyperliquid’s built-in TWAP slices an order into equal pieces over a chosen window, reducing market impact versus a single market order. Equal slices at equal intervals ignore whether the current moment is a good time to trade — the gap between a scheduler and an execution model, covered in the TWAP entry.