It does put (a little) pressure on prices, sure. Borrowing money to buy stocks puts a little extra upward pressure on prices. But neither is illegal, neither br

It does put (a little) pressure on prices, sure. Borrowing money to buy stocks puts a little extra upward pressure on prices. But neither is illegal, neither brings guaranteed profits (naked shorting is regulated so much exactly because of the risks to unrelated market participants if the stock goes up) and neither has the capability to directly harm the underlying company.