Bloomberg (Bloomberg) — China’s largest tech companies Alibaba Group Holding Ltd. and Tencent Holdings Ltd. have gained $66 billion in market value since May’s end, propelled by expectations of a gradual return to pre-crackdown growth and a litany of official promises to unshackle the private sector. Yet some investors warn the celebration may be premature.Most Read from BloombergEveryone Wants to Work at UPS After Teamsters DealWeWork Tumbles After Raising ‘Substantial Doubt’ About FutureTycoon Who Gave