Quote from lejmorro:
Guys, thank you, you are right! I hear you. I let my margin ratio get too high.
OK, then what is your maximum margin ratio in your account? 25%? 40%? higher? Presumably whatever it is, it will cover you from an unexpected assignment of say 10 short put contracts of SPY worth about $100K?
how much 'play' you leave depends on the margin computation of your broker and your positions. for something very volatile like occ-tims or span, i only use about 5-7% of available margin. for ib's pm, i would use about 15%. for reg-t, i'd use more because it's fairly stable.
the other thing is, i trade index options so i don't worry about assignment.