Calls Hot as Ballard Power Systems Inc., Plug Power Inc. Pop

Ballard Power Systems Inc. (USA) (NASDAQ:BLDP) has spiked 53.3% today to trade at $2.59, on news the fuel cell specialist will sell north of $80 million in patents to, and extend a service contract with, Volkswagen AG. BLDP's bull gap is having a halo effect on sector peer Plug Power Inc (NASDAQ:PLUG) -- which was last seen 6.5% higher at $3.26 -- and in both equities' options pits, call volume has accelerated.

BLDP calls, for example, are trading at 29 times what's typically seen at this point in the day, and are outpacing puts by a 3-to-1 margin. Most active is the equity's February 3 call, which is being bought to open. Delta on the call is docked at 0.26, suggesting a roughly 1-in-4 chance the option will be in the money at next Friday's close, when the front-month contracts expire.

Meanwhile, PLUG call volume is running at four times the average intraday pace this afternoon, and it appears some speculators are rolling the dice on an extended run north of $3 through March options expiration. Specifically, the March 3 call has seen the most action, and it seems a number of new positions have been purchased. Delta on this in-the-money call is perched at 0.67.

From a wider sentiment perspective, short-term speculators have taken different stances on BLDP and PLUG. Ballard Power Systems Inc.'s (NASDAQ:BLDP) Schaeffer's put/call open interest ratio (SOIR) of 0.53 ranks in the 72nd percentile of its annual range, meaning near-term traders are more put-heavy than usual toward the stock. Meanwhile, Plug Power Inc's (NASDAQ:PLUG) SOIR of 0.35 rests just 3 percentage points from a 52-week low, pointing to a distinct preference for calls over puts, among options set to expire in three months or less.