[Tech stocks sink in HK on renewed concerns about regulations as China slows the approval for online games] Hong Kong stocks fell by the most in six weeks as concerns about regulatory tightening in China revived after Beijing chastised mobile games developers and slowed the approval for new titles. Haitong Securities crashed amid a probe for market violations. The Hang Seng Index tumbled 2.3 per cent to 25,716 on Thursday, the most since a 4.2 per cent setback on July 27. The city’s tech benchmark sank 4.5 per cent, also the biggest loss since July 27. The Shanghai Composite Index...