Check out the companies making headlines after the bell Monday:
Yelp's shares popped Monday as a famous investor announced a new stake in the technology company. Greenlight Capital now owns shares of Yelp, which offers crowdsourced reviews of small businesses. Greenlight, helmed by vocal short-seller David Einhorn, predicts at least a 30 percent upside for the stock, according to an investor letter released Monday.
Shares of AIG sank in extended trading Monday after the insurance company posted earnings that fell well below Wall Street's estimates as market volatility weighed on turnaround attempts. AIG reported first-quarter adjusted earnings of 65 cents per share, below the $1 predicted in a Thomson Reuters consensus estimate.
"Although our first-quarter results were impacted by market volatility on investments, the underlying operating results demonstrate progress on our strategic objectives," said Peter Hancock, AIG president and chief executive officer, in a statement.
Anadarko Petroleum's stock fell after it reported mixed quarterly results. The oil-and-gas-exploration company posted a loss of $1.12 per share, ex-items, on revenues of $1.67 billion in the first quarter. Wall Street expected a loss of $1.16 on revenues of $1.81 billion, according to Thomson Reuters consensus estimates.
The company has been divesting from assets and restructuring its workforce as U.S. oil prices struggle to shake historic lows.
American Express shares tumbled as Wall Street digested news from the company's annual shareholder meeting, including the addition of a new board member. Ralph de la Vega, vice chairman at AT&T, was elected to the board, the credit card company said Monday.
Glass bottle maker Owens-Illinois bounced after it reported better-than-expected quarterly earnings. The beer and wine bottle company posted adjusted earnings of 48 cents per share, higher than the 40 cents expected by Wall Street, according to the Associated Press. Performance was boosted by the weakening of the U.S. dollar and the acquisition of Europe's Vitro.
Correction: This story was revised to correct Ralph de la Vega's status at AT&T. He is vice chairman.