Wal-Mart Stores, Inc.'s (NYSE:WMT - 70.70) options pits saw a flurry of put activity on Wednesday, with bearish traders placing last-minute bets ahead of this morning's earnings announcement. Around 31,000 contracts crossed the tape by the time the closing bell rang, more than tripling the average daily put volume. Short-term speculators set their sights on the out-of-the-money 67.50 strike, and scooped up WMT's 2/22 67.50-strike puts and March 67.50 puts. A healthy percentage at each strike traded at the ask price, implied volatility ticked higher, and open interest rose overnight, hinting at buy-to-open activity.

The 2/22 67.50-strike puts were purchased for a volume-weighted average price (VWAP) of $0.34 per contract. In other words, WMT must fall 5% below current levels by the end of the week -- when the options expire -- to breach breakeven at $67.16 (strike less the VWAP). As of Wednesday's close, delta for this position was perched at negative 0.25, or 25%, meaning the options market is assuming a 1-in-4 chance the puts will finish in the money by Friday's close.

Meanwhile, the March 67.50 puts were exchanged for a VWAP of $0.85, placing breakeven for these further-dated puts at $66.65, or 5.7% south of present levels. This particular group of option traders must be pretty confident in their bearish outlook, considering implied volatility at this put is inflated relative to the stock's 20-day historical (realized) volatility (22% vs. 13.6%). In other words, these speculators ponyed up a pricey premium to place these bets; however, their risk is limited to the net debit paid.

Digging deeper into the data reveals that bears have been circling around WMT in recent weeks. At the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX), traders have bought to open nearly two puts for every call during the past 10 sessions. The resultant put/call volume ratio of 1.90 ranks higher than 89% of other such annual readings, pointing to a healthier-than-usual appetite for bearish bets over bullish of late.

On the charts, WMT has added roughly 20% over the past 52 weeks. However, the stock has struggled in recent months, with the shares down around 9% from their all-time high of $77.60 -- which was reached on Oct. 16.

This downward trajectory has reversed course in today's session, however, after the Dow component reported a fourth-quarter profit that beat analysts' expectations. Additionally, the company raised its annual dividend payment by an historic 18% to $1.88 per share. At last look, WMT was up more than 2% to hover near $70.70.