Call volume is outpacing put volume on MasterCard (MA: sentiment, chart, options) heading into tonight's earnings report from the credit-card company. The call/put volume ratio today arrives at 1.33, with about 6,380 calls changing hands compared to 4,790 puts. The most popular call is MA's out-of-the-money November 160 strike, with more than 1,140 contracts changing hands. Meanwhile, the out-of-the-money November 130 put tops the list on the other side, with about 1,070 contracts crossing the tape.

Today's preference for calls over puts runs against the grain for MA, as the stock's Schaeffer's put/call open interest ratio (SOIR) of 1.03 indicates that puts outnumber calls among near-term options. Furthermore, this ratio ranks above 73% of all those taken during the past year, indicating that option traders have been more bearish toward MA only 27% of the time during the prior 52 weeks.

Looking at Wall Street's expectations, analysts are expecting MA to report a profit of $2.25 per share for the third-quarter - a 25% improvement over the same quarter last year. Historically, the company has bested these expectations in each of the past 4 reporting periods by an average of 20.9%.

While the company's bottom-line figure could come into play with an initial reaction, Stifel Nicolaus analyst Chirs Brendler told CNNMoney.com that "In our view, reported earnings-per-share will be less important than what management says about September and October spending trends, especially in Europe."

With less than 15 minutes until the close, MA was last seen trading down 2.58%. The stock attempted to rally out of the gate this morning, but was halted by overhead resistance in the 150 area, which is home to MA's declining 20-day moving average. The shares have not closed a session above their 20-day since September 19. Furthermore, traders should keep an eye on long-term resistance at the 170 level in case of a positive reaction to earnings, while support could kick in near 120 on disappointing results.