You can short it elsewhere.
Schwab won't let you, because even if you're 95% right, you'll still probably lose 95% of your money...
It's quite difficult to be 100% right...
You and your broker have to be pretty damn brazen to iron grip a highly liquid stock all the ways down to -95%.
You and your broker have to be pretty damn brazen to iron grip a highly liquid stock all the ways down to -95%.