Ah yes, the Flimflam-Fo Equation with its key parameters, "rich person a" and "rich person b".

Conspiracy theories might well be defined just by the application of the fallacy, "if someone benefits, then they intended it".

And here we see this fallacy being applied. Sound like a textbook conspiracy to me. The extremely weathly are not interested in increasing their net wealth, only in specific purchases to further their goals -- which are very easy to undermine with crashes.

People who are merely wealthy might possibly wish to increase their general wealth and therefore believe a crash will help them do that. That is an incredibly outsized risk for a wealthy person to needlessly take however.