The chart above, and the stock's historical volatility, can be a helpful guide in combination with fundamental analysis to judge whether selling the June 2014 put or call options highlighted in this article deliver a rate of return that represents good reward for the risks. We calculate the trailing twelve month volatility for Wal-Mart Stores, Inc. (considering the last 251 trading day WMT historical stock prices using closing values, as well as today's price of $77.84) to be 12%. In mid-afternoon trading on Monday, the put volume among S&P 500 components was 665,007 contracts, with call volume at 1.30M, for a put:call ratio of 0.51 so far for the day. Compared to the long-term median put:call ratio of .65, that represents very high call volume relative to puts; in other words, buyers are preferring calls in options trading so far today. Find out which 15 call and put options traders are talking about today.