Fusion Pharm, Inc. (FSPM)

[TraderGash]

There are usually few if any shares of overvalued OTC stocks available to short at any given time. The best source for smaller retail traders is Interactive Brokers. They have a public site which tells you the number of shares available for shorting.
https://www.interactivebrokers.com/en/?f=%2Fen%2Ftrading%2FSearchShortableStocks.php%3Fcntry%3Dusa%26amp%3Btag%3DUnited%252520States%26amp%3Bib_entity%3Dllc%26amp%3Bln%3D
If you search on a ticker and nothing shows up, then they have no shares available. They have no shares of FSPM available to short right now.
Insiders holding large blocks of free trading shares can manipulate the amount of shares available to short, and can trigger short squeezes by making shares available, and then pulling them, forcing the shorts to cover.