Just like the people that wouldn't divest in a company that uses slave labor or busts unions: They don't give a damn where the money comes from, as long as the money comes. How fucked up do you have to be to think "Hot damn, a massacre! Time to buy up stock in gun manufacturers!"
I really wish we could've gotten gun control in steps, instead of trying to pass a larger bill with multiple things. If we could've gotten a quick ban on the sale or transfer of large cap magazines the gun industry stocks would probably be tanking.
“but what should we do when the highborn and wealthy take to crime? Indeed, if a poor man will spend a year in prison for stealing out of hunger, how high would the gallows need to be to hang the rich man who breaks the law out of greed?” Terry Pratchett, Snuff