I haven’t let one expire yet, but that looks right. I don’t anticipate any major problems because none of the sources I’ve seen mention any, and besides all legs expire on the same day.
Note that the loan value already has to be within margin borrowing power throughout the entire duration of the loan, since your broker takes into account the box spread as a negative-value asset when calculating margin. Box spreads can’t get you more borrowing power (it’s box spread financing, not box spread borrowing).
I haven’t let one expire yet, but that looks right. I don’t anticipate any major problems because none of the sources I’ve seen mention any, and besides all legs expire on the same day.
Note that the loan value already has to be within margin borrowing power throughout the entire duration of the loan, since your broker takes into account the box spread as a negative-value asset when calculating margin. Box spreads can’t get you more borrowing power (it’s box spread financing, not box spread borrowing).