china is tightening approvals for quantitative hedge funds in the latest sign that officials are concerned about the potential market impact of trading driven by algorithms after a year of rapid asset expansion the asset management association of china which approves registration of new quant funds closed a fasttrack channel in recent weeks for at least some managers according to people with knowledge of the matter who asked not to be named discussing private information the association has also rejected applications that use token amounts to launch new offerings the people said