Most Active Options: Bank of America Corp and Citigroup Inc

The 20 stocks listed in the table below have attracted the highest options volume during the past 10 trading days. Stocks highlighted are new to the list since the last time the study was run, and data is courtesy of Schaeffer's Senior Quantitative Analyst Rocky White. Two notable names are bank stocks Bank of America Corp (NYSE:BAC) and Citigroup Inc (NYSE:C).

It's been a dreary time for financial stocks, as low interest rates weigh on the sector. In fact, despite a recent rally amid expectations the Federal Reserve was on the cusp of raising interest rates, bank stocks came crashing back down to earth in the wake of this week's policy decision from the Fed. Adding to the risk-off backdrop is next week's "Brexit" vote, but BAC options traders don't seem to mind.

In fact, over the past five sessions, the six strikes seeing the largest open interest increases on BAC have been calls. Specifically, the stock's June 13.50 call has seen the biggest increase, with almost 28,000 options added. It looks like a healthy portion of this activity was of the buy-to-open kind, meaning speculators expect the stock to rally north of the strike by tonight's close, when the front-month options expire.

Technically, Bank of America Corp has been a dud over the past 52 weeks, down nearly 23%. Plus, although the shares tiptoed above $13.50 earlier, they were last seen below this mark at $13.30. Regardless of where the stock settles tonight, risk for the call buyer is limited.

Call buying has been popular in C's options pits in recent months. At the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX), for instance, the stock's 50-day call/put volume ratio of 2.02 ranks in the 76th annual percentile.

Echoing this is the equity's Schaeffer's put/call open interest ratio (SOIR) of 0.70. Not only does this show that calls outweigh puts among options expiring in three months or less, but it ranks in the 14th annual percentile. In other words, short-term speculators are more call-heavy than usual toward C.

Today, however, it's put players who are active in C's options pits, with puts crossing at two times the average intraday pace. It looks like one speculator may be rolling his June 43 puts down and out to the July 42.50 strike, although it's not clear whether these soon-to-be front-month puts are being bought or sold. Technically, Citigroup Inc has struggled in step with BAC, down 25.5% year-over-year at $42.29.

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