If only shorting was so easy everyone would have shorted LEXG on 4/28 at 10.68. According to Tim Sykes post the next day (4/29) there were limited LEXG shares available to short.
Sykes 4/29 post
...I’ve been focusing on blatant pump & dumps Lithium Exploration Group Inc (LEXG) and Lithium Corporation (LTUM) ... the past 2 days and while I would’ve LOOOOOOOOVED to short LEXG at $5,6,7,8,9, as I posted, there simply were soooo few shares to short so I got nothing.