I own 150 shares of Tesla, purchased at different times over the past few years. Since the split, I've done very well selling Puts and Calls. (Since you have to buy/sell options in lots of 100, TSLA options were outside my comfort range prior to the split!) The stock's volatility has resulted in some very attractive options trades. Also, I'm a long-term believer in the company and it's future, so I believe in the underlying security, rather than just "trading a name."
As of Oct. 30, only 6.46% of TSLA was short - there are dozens and dozens of stocks with a higher percentage of shares short. However, when you do the calculation by market cap, then Tesla ends up near the top, as 6.46% of a $434 billion market cap is a lot of money! Percentage of shares is more relevant data, as a higher number of shares short can lead to a classic "short squeeze" when the stock prices rises, then begins to get "artificially" inflated as the shorts buy shares at higher and higher prices to cover their positions.