Price doesn’t match the tick size
Every market has a minimum price increment. Type a price that isn’t on that grid and the order is rejected before it reaches the book. Use the price step buttons in the ticket, or let the field round it for you.
Order notional is below the $10 minimum
Size times price has to clear a $10 minimum order value. Increase the size or use a higher-priced market.
Insufficient balance or margin
Your available margin can’t cover this order at the leverage and margin mode you have set. Reduce the size, add margin, or raise your leverage for this market.
Post-only order would immediately match
An ALO (post-only) order is rejected instead of matching immediately, that’s the point of using one. If it keeps happening, the market moved past your price between typing it and submitting, or you’re pricing it inside the current spread. Reprice further from the touch, or use Chase if you want it to track the touch automatically.
Reduce-only order would increase your position
A reduce-only order can only shrink or close your existing position. If the side or size you set would grow it instead, it’s rejected. Check which side you’re on before setting reduce-only.
Builder fee has not been approved
Trading needs the one-time builder fee approval from setup. If you disconnected before finishing it, or revoked the approval on Hyperliquid directly, run the connect flow again to re-approve it.