Convertible-arb hedge
Shares sold short not as a bet the stock falls, but to hedge convertible notes the same investor owns. These shorts show up in the headline Short interest (SI) number, but they are not directional bets and are far less exposed to a squeeze — the hedge profits from the structure, not the direction. Borrow recalls, financing changes, or a hedge unwind can still force trading, so "less squeezable" is the honest claim, not "immune".
A company can even supply the shares itself: lending stock to a bank so that convertible-note buyers can delta-hedge is a standard financing structure, disclosed in the company's own filings. The result is a large, mechanical block inside SI that behaves nothing like a directional short — it does not panic, does not cover into strength, and does not pay up to borrow. Decomposing SI into hedge versus directional bet is the first arithmetic step of squeeze forensics; skipping it is how a financing arrangement gets mislabeled as a third of the company betting against itself.