BEIJING -- In one of the most hyped, superlative-laden China deals in recent memory, shares of Industrial & Commercial Bank of China climbed 15% in their first day of trading in Hong Kong Friday. The bank raised about $19.1 billion in the offering, the largest IPO in history. In a simultaneous Shanghai listing on Friday, ICBC shares also gained. The warm reception was the latest in a string of such Chinese listings. In the U.S., shares of budget hotel operator Home Inns & Hotels ( HMIN) closed up 63% in their first day of trading Thursday. Recent debuts from Mindray Medical ( MR) and New Oriental Education & Technology Group ( EDU) have also been well-received. But even as China bets go, ICBC has won an extra degree of attention as the biggest bank in the world's most populous country. At year-end 2005, ICBC held $726 billion in deposits, equivalent to 19% of all China's bank deposits. It has more than 2.5 million corporate customers, and personal customers exceed 150 million. Edmund Harriss, manager of the Guinness Atkinson China and Hong Kong ( ICHKX) fund, says he bought shares because he expected to see a mild pop on the IPO. However, he remains "somewhat cautious" on the financial sector and isn't sure if he'll buy more. "This is very much a proxy on the banking sector in China ," Harriss says. "I'm OK about having some in my portfolio, but I would be unlikely to chase it." Harriss also believes Chinese banks aren't cheap. "The valuations we are seeing are based on a growth profile that is undoubtedly there, but takes no account of any slips or speed bumps along the way," Harriss says. "If we find that nonperforming loans pick up, one needs to be aware that these banks are expensive relative to their peers in the region." He isn't the only skeptical investor.