In a significant regulatory move, the China Securities Regulatory Commission (CSRC) has introduced major changes to quantitative (quant) trading practices in the Chinese market. These changes include a ban on selling within the first 30 minutes of the market opening and closing, as well as prohibiting short selling by certain Designated Market Value (DMV) accounts. This decision comes in the wake of a tumultuous period for China's stock market, which saw extreme volatility over a two-week span, leading to unprecedented failures in the trading models of quant hedge funds. Some of China's largest quant funds, managing assets worth tens of billions of yuan, have been significantly affected. The market's instability has prompted calls for increased regulation, with quant hedge funds admitting to the inadequacy of their stock-trading models during this period. The recent market events have been described as a 'quant quake', with hedge funds flailing in the face of what has been termed the first 'real' liquidity event for China's quant funds, forcing them to sell off valuable assets. The CSRC's actions follow a three-day ban on a prominent fund and come ahead of the pre-Lunar New Year period.