Last Friday I got a warning from Schwab that I had violated their rule on trading with unsettled cash on one of my trades. They told me if it happened again they would put limits on my account. When I want to make a trade and I see cash available to trade I am in a hurry and it doesn't specify whether or not it is settled or unsettled cash. Normally I transfer enough cash from my Schwab bank account ahead of time to do the trade but I was in a hurry and had been doing numerous trades. I haven't receive any messages regarding option expiration duration time.