China has a new most valuable listed company, and it makes the chips inside your phone. CXMT, formerly ChangXin Memory Technologies, closed its Shanghai debut up 466% on Monday, the South China Morning Post reported. That values the Hefei firm at 3.28 trillion yuan, or about $485bn. The numbers are hard to overstate. CXMT priced its IPO at 8.66 yuan a share, opened at 49.50 and touched 55.03 during the session. It raised 57.92 billion yuan, about $8.6bn, rising to $9.8bn if the overallotment is exercised. That is Asia’s biggest listing this year, and the second largest in Chinese history...