Can ETFs be short-squeezed? I'm not familiar with how they work.
For ETFs like SPY, it seems it buys and sells stocks in the portfolio. For ETFs like UVXY, it seems it has no real stocks.
How does short-squeeze work for these two kinds of ETFs?
A short squeeze on SPY or similar large index ETFs will never work as Authorized Participants will exploit the pricing difference to prevent the ETF from straying from the NAV. Since the underlying is so large it will be hard for it to move due to this arbitraging.
For items ETFs UVXY, the same arbitraging will occur, however, since its underlying is less liquid the NAV would also move towards the ETF price. (albeit not by much)