Calls have been in high demand on Medtronic, Inc. (NYSE:MDT - 41.19) lately, per data from the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX). During the course of the past 10 sessions, traders have bought to open four calls for every put on the stock. What's more, the resultant call/put volume ratio of 4.00 ranks higher than 82% of other such readings taken in the past year, implying bullish bets have been accumulated over bearish at an accelerated clip in recent weeks.

This trend is echoed by the stock's call-skewed Schaeffer's put/call open interest ratio (SOIR) of 0.42. Not only does this show that calls outweigh puts by a more than two-to-one margin among options expiring in three months or less, but it ranks in the 14th percentile of its annual range. In other words, short-term speculators are more call-heavy than usual toward MDT.

Calls won the numbers race in Thursday's session. More than 5,300 of these contracts changed hands throughout the day, compared to fewer than 5,000 puts. The most popular strike was MDT's February 42 call, which saw roughly 2,200 contracts cross the tape. The majority of these went off at the ask price, implied volatility moved higher, and open interest added 1,371 new positions overnight, hinting at buy-to-open activity.

By purchasing these near-the-money calls to open for a volume-weighted average price (VWAP) of $0.73, traders will begin to profit with each step north of $42.73 (the strike price plus the VWAP) MDT takes through February expiration. This breakeven level represents a 3.7% premium to the stock's current perch.

On the charts, the medical equipment maker has advanced a modest 7.7% year-to-date. More recently, the equity has been stuck churning in the $41-to-$43 range since mid-October. Should the equity fail to topple the $42.73 mark by Feb. 15, though, the most yesterday's call buyers stand to lose is the initial premium paid.