Comment by mlin on The Box Spread Trick: Get rich slightly faster · 2021-03-25T23:05:25.226Z · LW · GW

Are there any details to be concerned about how this settles at expiration?

For example, is the following all correct? However the market moved,

1. one of the short legs is assigned for you to settle with cash -- possibly an enormous amount thereof!
2. one of the long legs is in-the-money by the same amount, minus the loan value; and exercises automatically (assuming you didn't specify contrary instructions)
3. the other two legs expire worthless
4. your only required action is to ensure the loan value is on-hand in the account (or within margin borrowing power) at this time

Could anything possibly go wrong here?