Quote from xflat2186:
Bingo, MTE nailed it head on. You're underlyings offset each other so all you've done is write a naked call. Your broker will look at that position and ask why you bothered with the underlyings and just margin you on the naked call.
Yes you keep the premium but you will lose money as the ETF rallies. The two ETF's offset each other.
Thanks xflat. I understood most of what you said and you're right that the positions offset each other. Perhaps from the brokers point of view you are naked but your risk isn't similar, since you actually own the underlying, no?