Baidu’s Hong Kong shares plunged on Monday, wiping out $2.4 billion from its market value. The company’s stock dropped as much as 8.8%, before closing down 7%. Baidu became the biggest loser on both the Hang Seng index and the Hang Seng Tech index. The sharp decline followed speculation triggered by the absence of Baidu’s founder, robin li, at a rare symposium hosted by President Xi Jinping in Beijing.