Funny to see this margin interest balance on my account. What happened is I got early assignment on short SPY puts and forgot to liquidate SGOV the Monday before options expiration week. This is one day of margin interest so Schwab got their pound of flesh. Remember kids always plan ahead for the chance of early assignment.
Yup someone was long SPY only part of my short position was assigned early the rest I got delivery on Saturday as usual.
For the portion you weren't assigned, you earned (a little bit). Exercising puts isn't well understood. When I traded for the Bank, we were more focused on dividends because our financing was so cheap. We financed better than Libor.