Information provided by Theflyonthewall.com

Yahoo (YHOO) shares gained almost 3% after its CEO Scott Thompson relented to pressure and stepped down following a firestorm over a computer science degree he never received.

The company also reached a deal with activist shareholder Dan Loeb of Third Point, who had initially disclosed Thompson's resume problems, as the company agreed to allow Loeb and two other Third Point nominees to join its board.

Another recently embattled company, Chesapeake Energy (CHK), jumped 7% after the company said it had arranged for a $3 billion unsecured loan to aid its financial flexibility as it continues to sell off assets. Also, the Wall Street Journal reported that activist investor Carl Icahn will likely reveal he once again has increased his stake in Chesapeake, and the company said on its call to discuss its financing that it "wouldn't be surprised" if Icahn becomes a large shareholder.

JPMorgan Chase (JPM) continues to deal with the fallout of its $2 billion trading loss, as the bank announced that its Chief Investment Officer Ina Drew will retire, to be replaced by Matt Zames, and the bank's stock fell another 2%.

Best Buy (BBY) Chairman Richard Schulze will step down when his term ends after the company's investigation into its former CEO Brian Dunn found that Dunn violated policy by engaging in an inappropriate personal relationship with a female employee and Schulze failed to bring the matter to the board's audit committee when he first learned of the allegations.

Among the notable market gainers Monday were Golfsmith (GOLF), up 28%, after agreeing to be acquired by Canada's Golf Town for $6.10 per share in cash, and Citizens South Banking (CSBC), up 24%, following its announcement that it will merge with Park Sterling Corporation (PSTB). Also higher were shares of Avon (AVP), up more than 4%, after the company responded to the latest $24.75 per share buyout offer from Coty, but asked for another week to make a decision on the bid.

Noteworthy losers Monday included Ancestry.com (ACOM), down 13%, following NBC's decision not to renew the TV show "Who Do You Think You Are?", and InterOil (IOC), down 9%, after the company got notice from Papua New Guinea of the state's intention to cancel an LNG project agreement.