Shares of SLM Corp. (SLM) are trading flat on the session; currently shares are off just 0.06%, at $15.69. The stock has been rallying for the past three months, holding the 50-day moving average on each test. Shares of SLM are testing the 50-day once again.

One institutional trader is betting that shares find support here. Yesterday, the January 2013 $19 call was purchased 4,150 times, on the offer, for $0.21.? Total volume on the strike reached 5,050 contracts by the end of the session; open interest was just 348 contracts.

Today?s OI confirms new positioning in the name, now at 5,352.

Overall call volume registered 17.5x normal volume by the end of yesterday?s session, with over 90% of all contracts being purchases on the offer.

Overall implied and historical volatility is registering 21% and 20%, resepctively, which is down from 52% and 70% just nine months ago.

SLM Corporation is a holding company operating through its various subsidiaries. The company’s primary business is to originate, service and collect loans it makes to students and/or their parents to finance the cost of their education.