Better return to the original topic: What to do if you're assigned early on a short option in a multi-leg strategy?
Just trade out of the stock position and re-enter if you're that worried...
I'm just explaining that outside the 3 situations I mentioned, early assignment makes you money. So that would be a good thing...
In the 3 situations that early assignment is likely, the option will have a delta of 1, since the call value will be intrinsic only. If the delta is <1, it means the option has some value above intrinsic. Which means that if you are assigned, you basically capture that extra value instantly. For example, if you're assigned in an ATM (delta50) call, which has a value of say 1.20... you will be short 100 shares per call (usually 100 is underlying size), but you can buy back the shares at market open and basically have earned the 1.20 minus the value the stock trades above the ATM strike. Max earning can be more, if stock traded below strike... no loss possible on this, even is stock trades 10% higher since you would've lost on the short call anyway. So yay!
Indeed only American style options can be assigned early, so no worries with European style.
@donnap , you will not lose on assignment before dividend, since the call value is intrinsic to the stock value before dividend.
The only way you can get caught in a shit storm is when you're assigned early in uncovered calls and for some reason you're stuck in with short stock position with high rates in the middle of some corporate action, takeover/merger or bankruptcy and you don't know what you own or get or have to deliver...