Microsoft (MSFT, news, chart, volatility) call options are actively traded. 88,000 traded, compared to 23,000 puts. Jan 24 and April 21 calls are the most actives after a firm bought 4,370 Jan 22.5 calls and 18,646 Jan 24 calls, while selling 12,731 April 21 calls. With shares up 16 cents to $20.49, some of the activity might reflect some bullish trading in Microsoft ahead of an update to financial analysts at a conference later this week. Earnings due out on the 22nd, after the Jan expiration.