Bankrate Inc. (RATE) added 5% to $40.37 today after the company was initiated with a buy rating at American Technology Research with a price target of $48.

Ceragon Networks Ltd. (CRNT) shares jumped over 16% after the Israeli wireless provider reported first-quarter net earnings of $2.62 million, or 9 cents per share, up from $228,000, or one cent per share, a year ago. Revenues rose to $33.9 million from $21.3 million a year ago. Analysts were expected 9 cents per share on revenues of $32.4 million.

Datawatch Corp. (DWCH) shares rallied 25% after the enterprise information management applications provider reported second-quarter earnings of $424,000, or 7 cents per share, up from $227,000, or 4 cents per share, a year ago. Revenues rose 14% to $6.1 million for the year.

Ionatron (IOTN) shares jumped 21% after the U.S. Navy posted a notification on the Federal Business Opportunities Web site about the award of a sole source contract regarding the company's Counter IED technology. Ionatron disclosed the posting of the contract which is worth about $500,000.

Sigma Designs (SIGM) shares dropped 12% after the company was downgraded to sell from neutral at American Technology Research.

Rigal Pharmaceuticals (RIGL) dropped 6.2% after the company said that it plans to sell five million shares under an existing shelf registration statement with an over-allotment option for an additional 750,000 shares to the underwriters.

Citigroup (C) management is reportedly concerned that the company could become an activist takeover target, according to a report by the Financial Times. The executives are concerned that the company may represent an attractive breakup opportunity, while many dismiss the rumors on grounds of its size.

Merrill Lynch (MER) said it would buyback $6 billion in shares.

Dominion (D) agreed to sell its Gulf of Mexico assets to Italian energy group Eni (E) for $4.8 billion.