Of the 20 equities seeing the heaviest options volume in recent sessions, three names of notable interest this afternoon are Cisco Systems, Inc. (NASDAQ:CSCO - 21.32), Citigroup Inc. (NYSE:C - 43.88), and American International Group, Inc. (NYSE:AIG - 38.13). Here is a quick look at today's interesting activity in these options pits.

Cisco Systems stretched to a new 52-week high of $21.67 this morning before tumbling into the red. Call buyers have emerged nonetheless, sending the April 22 call to the top of the list of most active CSCO options. More than 9,100 contracts have traded here, 86% of which crossed at the ask price. With implied volatility moving higher, it is likely some of these are being purchased to open, at a volume-weighted average price (VWAP) of $0.32. Breakeven at expiration is therefore $22.32 (strike plus VWAP), or about 4.7% above the stock's current perch. Today's activity notwithstanding, puts have been a popular choice among CSCO speculators in recent weeks, relatively speaking. The 50-day put/call volume ratio measuring buy-to-open orders on the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) stands at 0.46. While this does mean just 46 puts have been bought to open for every 100 calls (during the last 50 trading days), the ratio is higher than 72% of the past year's worth of readings. In other words, option traders are more bearishly aligned now than they have been more than two-thirds of the time in the past year.

Put volume is handily outpacing call volume in Citigroup today, with 45,000 puts changing hands versus 38,000 calls. The most active put so far is the January 2014 45 strike, where more than 4,100 contracts have traded. The lion's share of this volume has gone off at the ask price, and implied volatility has edged higher, indicative of new purchases. This is a longer-term bet that C shares will stumble in the upcoming months. Today's VWAP on this put was $5.21, resulting in a breakeven price at expiration of $39.79 (strike less VWAP). Delta on the in-the-money option currently stands at negative 0.46, meaning the options market is pricing in a roughly 1-in-2 chance that Citigroup will be trading south of the 45 strike when these options expire in 331 days. Currently, however, the stock is still enjoying a longer-term uptrend that has seen it appreciate roughly 75% since its late-July trough.

Finally, American International Group speculators may be a little anxious ahead of tomorrow evening's earnings report. Put volume is currently outpacing call volume by nearly 3-to-2, and is running 44% above what's typically seen on an intraday basis. While the weekly 2/22 37.50-strike put is today's most active position, the March 38 put is a very close second. Volume at this strike overall appears to be a mix of buying and selling, and one block of 5,000 contracts traded off the bid and was tied to a stock purchase, perhaps as a delta neutral play on increased volatility. The weekly options, meanwhile, have seen some buying demand, with the majority of the orders trading off the ask price. Volume easily trumps open interest at this soon-to-expire strike, with 6,700 contracts changing hands today versus existing open interest of 898.

The 20 stocks below have attracted the highest options volume -- in the front three-months' series -- during the past 10 trading days. Data is courtesy of Schaeffer's Senior Quantitative Analyst Rocky White.