So I've placed several orders this morning and am not getting filled, even though I see the spread trading at a greater spread than my my limit order. I thought that all lesser limit orders must be filled before the spread can increase? For example, one of my orders is for 10/10 contracts for a .30 limit, and the spread is currently at .55! Just sleepy, boring day with not enough volume, eh? They are low volume puts, so that's it, right? The orders are for vertical bull put credit spreads on the S&P 500.