I believe throwawaysea's point is that the one thing has nothing to do with the other. Essentially, the bank weighing in saying "We don't believe your customers

I believe throwawaysea's point is that the one thing has nothing to do with the other. Essentially, the bank weighing in saying "We don't believe your customers are good for this amount of money you claim they are good for." is, at heart, just financial prudence on the part of a trade's 3rd party backer. The other is criminal collusion on the part of people on the other side of a trade. But the 3rd party backer doesn't care about any of that as horrible as it may sound. They just want to be sure they can get their money from both sides, and they're not at all sure about that with these GME/BBY/AMC et al trades.