MannKind Corporation (MNKD) calls have seen seen tons of action in the past two weeks
Calls have been the options of choice among MannKind Corporation (NASDAQ:MNKD) speculators of late. Specifically, during the past 10 sessions, traders have bought to open nearly 12 calls for every put at the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX). The biopharmaceutical company's resulting 10-day call/put volume ratio across these exchanges comes in at 11.75 -- higher than 88% of all such readings from the past year.
Reinforcing this preference for calls over puts is MNKD's Schaeffer's put/call open interest ratio (SOIR) of 0.32, which is just 3 percentage points from an annual low. In other words, call open interest roughly triples put open interest, among options expiring in the next three months. 
However, it should be noted that some of this activity could be the result of short sellers protecting their bets, as close to 30% of the security's float is sold short. It would take over three weeks for short sellers to buy back these positions, at the stock's average pace of trading.
While MannKind Corporation (NASDAQ:MNKD) has added over 17% in the past 52 weeks, it's struggled of late. Since touching a multi-year high of $11.48 on June 30, the shares have dropped 44.5%, but were last seen 1.4% higher at $6.37.