Microsoft Corporation (NASDAQ:MSFT - 27.98) has seen heavy option volume on two short-term calls today, and it is likely the work of one party. In fact, it looks as though this Microsoft bull is closing out of a front-month, at-the-money position in favor of a slightly longer-term and higher-strike play.

Turning to the specifics, a block of 18,051 February 28 calls traded at the bid price of $0.18 per contract. At the same time, a symmetrical block of the Microsoft March 29 calls changed hands at the ask price of $0.15 apiece. Although open interest exceeds volume in both cases, it appears likely that the front-month calls were sold to close and the back-month calls were purchased to open, for a net credit of $0.03 per spread.

The February option notwithstanding, breakeven for the March call is $29.15 at expiration, or the strike price plus the premium paid. This is more than 4% above the stock's current price, and is territory Microsoft has not explored since early November. As such, delta for this option currently stands at 19, revealing a less than 1-in-5 chance the option will be in the money by expiration on March 15. Above breakeven, call buyers can enjoy unlimited gains. South of the strike price, however, losses are capped at the modest debit paid.

Call buyers have been flocking to Microsoft Corporation of late, as evidenced by data from the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX). The 50-day call/put volume ratio measuring buy-to-open activity across this trio of exchanges stands at 2.84, or 3 percentage points away from a new annual high. In other words, rarely have option speculators been so drawn to the call side of the fence. Over the short term, the 10-day call/put volume ratio is 2.89, in the 78th annual percentile.

In similar fashion, the Schaeffer's put/call open interest ratio (SOIR) for Microsoft is 0.57, indicating there are nearly twice as many calls open as puts among options expiring in the next three months. This, too, is near an optimistic peak, as the reading is 2 percentage points shy of an annual low.

All of this bullishness is slightly puzzling, given Microsoft Corporation's anemic showing on the charts. In the last 12 months, the stock has dropped more than 7%. What's more, looking back to late 2009, the shares have been mired in a sideways trading pattern between $24 and $32. The stock is currently hovering around the middle of this range.