What are China’s quantitative trading funds, and why are they so controversial?

Quantitative trading, a method that employs advanced algorithms and artificial intelligence to generate substantial returns, has been a dominant force in China's stock market for years. These computer-driven strategies have become a powerful catalyst for trading activity and liquidity, even as traditional stock-pickers have struggled to maintain their edge.

However, this rise in popularity has also sparked controversy, particularly during times of market instability. Critics argue that the widespread adoption of quant strategies during turbulent periods can exacerbate volatility, as retail investors, who still control a majority of the market, trade against sophisticated computer algorithms.

The size of China's quant trading industry has surged in recent years, with quant-focused private funds reaching a staggering 3 trillion yuan (US$444.5 billion) in size in the previous year. The number of quant funds managing over 10 billion yuan has increased from 55 at the end of 2025 to over 70 by June of the current year, representing nearly half of all China-based funds exceeding that threshold.

Major players in this field include Hangzhou-based High-Flyer, which operates exclusively with its own capital and gained international recognition for its AI trading systems and support for DeepSeek. Other significant firms include Ubiquant, Minghong Investment, and Yanfu Investments, each managing between 80 billion yuan and 90 billion yuan.

These top-tier quant funds delivered average gains of more than 30 percent in 2025, attracting a flood of new capital. Globally, quantitative trading is dominated by large, systematic firms and multi-strategy entities managing hundreds of billions of dollars. In the U.S., Man Group leads with assets under management of approximately US$253.6 billion, while Two Sigma and AQR Capital Management oversee around US$75 billion and US$187 billion, respectively.

Meanwhile, Renaissance Technologies operates with roughly US$64 billion, including its renowned Medallion Fund. Despite its impressive performance, quantitative trading remains a contentious issue in China. During a July 20 meeting chaired by China Securities Regulatory Commission (CSRC) chairman Wu Qing, investors called for stricter regulations governing the development of quantitative trading and AI.

One primary reason for the controversy is the potential for quant strategies to amplify market swings. When many funds rely on similar models, a minor price movement can trigger synchronized selling, placing additional pressure on already declining markets. Another concern is the perceived advantage that technology and information provide to quant funds over retail investors, who still dominate the market.

This debate has gained renewed attention following a government inquiry into former CSRC vice-chairman Fang Xinghai, who advocated for greater access to quantitative and foreign hedge funds. Chinese authorities have responded to these concerns by tightening oversight of quantitative and program trading. Emphasis has been placed on transparency, monitoring abnormal trading activities, and mitigating the historical latency advantages enjoyed by high-frequency traders.

In September 2023, major mainland China exchanges introduced a reporting system requiring quant investors to disclose information such as trading accounts, strategies, software, and related systems. New participants must complete this reporting before engaging in any trading activities. In July 2025, regulators unveiled the first comprehensive framework for program trading, targeting traders executing over 300 orders per second or 20,000 orders daily.

This framework imposes higher traffic and cancellation fees on high-frequency strategies and bans same-day short selling via stock lending. Additionally, China has set a stringent 50 percent order cancellation threshold, far stricter than the 90 percent level in the U.S. and 70 percent in Japan.