Why is GameStop’s stock suddenly up by 13%?

GameStop stock is suddenly up by about 13% because traders are reacting to a reported plan that sounds almost absurd on paper: GameStop (NYSE: GME) may try to buy eBay (NASDAQ: EBAY). The retailer was worth around $11 billion at Friday’s close. EBay was worth about $45 billion. That is not a normal-sized gap. That...