So if a retail punter follows advice found on something called...

So if a retail punter follows advice found on something called falling knives or whatever, then I'd say you're making a much stronger case that unadvised punters should not be allowed to trade. Panic sellers using the short term movements in the price as being meaningful for valuation are the same... they are reacting to something irrelevant and ought not be trading financial instruments.

In the case of MFG, there has been plenty of discourse here about valuation, most of which leans to the current price being a bargain in some medium term sense. You now have some new information about flows, which is not great. The debate is about whether that can be turned around, whether costs can partly offset the reduction in revenue and whether the dividend yield is sustainable. Notice that the level and change in short interest is irrelevant to those things. You're worrying about the wrong things.