The shares of EMC Corporation (EMC: sentiment, chart, options) are struggling to find a foothold in positive territory this morning following a downgrade from Calyon Securities. The brokerage firm slashed its opinion on EMC from "buy" to "sell," asserting that "now is a great time to take money off the table."

Calyon cited a host of concerns for EMC, including persistent IT spending weakness and negative checks on IBM (IBM) and Sun Microsystems (JAVA). The broker is also troubled by lowered guidance for EMC's sector peer NetApp (NTAP), along with Altera's (ALTR) comment that it expects softness in computers and storage.

After dropping nearly 4% out of the gate this morning, EMC has elbowed its way to a fractional gain. At last check, the shares were up 10 cents at $11.27.

While the stock is hardly worse for the wear after today's downgrade, put volume is dominating EMC's option pits. The most active option this morning is the December 10 put, with volume of 2,469 contracts crossing the tape on open interest of 17,527.