Puts have been preferred on Costco Wholesale Corporation (NASDAQ:COST - 101.90) in recent weeks, as evidenced by data at the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX). Specifically, the stock's 10-day put/call volume ratio of 1.20 ranks higher than 82% of other such readings taken in the past year, indicating puts have been bought to open over calls at an accelerated clip of late.

This trend is echoed in COST's Schaeffer's put/call open interest ratio (SOIR) of 1.16. Not only does this show put open interest outweighs call open interest among options with a three-month shelf-life or less, but it ranks in the 59th percentile of its annual range. In other words, short-term speculators are slightly more put-heavy than usual toward the stock.

However, amid news of better-than-expected quarterly earnings, as well as a special dividend announcement, option players turned their attention to COST's calls in Wednesday's session. Around 25,000 contracts crossed the tape, representing more than six times the average daily volume for call options. By comparison, roughly 16,000 put contracts changed hands.

Near-term traders circled around COST's December 105 call, which emerged as the most-active strike on the day. A healthy majority of the near 5,000 contracts traded at the ask price, and open interest soared overnight -- two indications of buy-to-open activity.

By purchasing these out-of-the-money calls, traders expect COST to rally above the $105.66 mark (the strike plus the volume-weighted average price [VWAP] of $0.66) by December expiration. This breakeven level not only represents a slim 3% premium to Wednesday's closing price of $102.58, but also uncharted territory for the stock.

Technically, COST has had a respectable showing on the charts for some time now. For starters, the stock has been ushered steadily higher atop its 32- and 60-week moving averages since September 2010. Additionally, the shares have added around 23% in 2012, including yesterday's 10.8% earnings-induced pop.

Given COST's technical tenacity, this recent run on puts at the ISE, CBOE, and PHLX seems a bit surprising. However, with the stock's Relative Strength Index (RSI) of 66 teetering near overbought territory, this activity could simply represent shareholders protecting profits against a potential pullback.

At last check, COST was down 0.6% in early trading to hover near $101.90. Should the stock fail to topple the aforementioned breakeven level by Dec. 21, the most Wednesday's call buyers stand to lose is the initial premium paid.