Options traders have been snapping up calls on Zynga Inc. (NASDAQ:ZNGA - 2.16), according to data from the major exchanges. During the past five sessions, speculators on the International Securities Exchange (ISE) and Chicago Board Options Exchange (CBOE) have bought to open 11,887 calls on ZNGA, compared to only 538 puts. In other words, about 22 times more bullish bets than bearish have been purchased on the gaming stock.

From a broader view, speculative players have bought to open 2.99 calls for every put on ZNGA over the past 10 days, based on cumulative data from the ISE, CBOE, and NASDAQ OMX PHLX (PHLX).

Of course, with the stock trading around $2 per share, this preference for calls over puts isn't terribly surprising. Given the low share price, there simply aren't very many viable put strikes available with which to bet on a bearish move.

Plus, there could be an ulterior motive for the recent uptick in ZNGA call buying. Short interest has crept steadily higher in recent weeks, having increased by 5.5% during just the most recent reporting period. When buy-to-open call volume and short interest are rising simultaneously -- particularly on an underperforming stock -- it can be indicative of hedging activity on the part of the bears.

And ZNGA has certainly emerged as an underperformer, with the shares down 77% year-to-date. In recent months, the stock has been pressured lower by resistance at its 10-day, 20-day, and 50-day moving averages.