The recent global tech stock correction in July has put quantitative trading under intense scrutiny, with social media abuzz with debates over market fairness, alleged "quote stuffing," and concerns about de facto T+0 capabilities.

Contrary to popular belief, major quantitative hedge funds were net buyers rather than sellers during the sharp July selloff. Data from Haoma Fund Research Center shows quant long-only strategies posted an average -16.94% return in July, ranking last among all strategies for the month, and are down 2.81% year-to-date. Industry insiders note that these funds typically maintain high net equity exposure and would incur significant impact costs from forced selling, making it an unlikely strategy for generating alpha.

Regulators are actively addressing fairness concerns. The China Securities Regulatory Commission (CSRC) and stock exchanges have implemented measures including migrating trading data access from local area networks to wide area networks, effective July 31, and banning brokerages from placing client equipment in exchange server rooms or providing dedicated trading units. These changes aim to level the playing field between institutional and retail investors.

Since November, exchanges have also strengthened oversight of algorithmic trading by introducing monitoring metrics for "abnormal order submission rates" and "frequent flash cancellations." These steps are designed to prevent technology-driven advantages from creating systemic unfairness.

One persistent misconception is that quants can trade T+0 while retail investors are restricted to T+1. In reality, all investors in A-share secondary markets follow the same T+1 rule: shares bought today cannot be sold until tomorrow. While some exchange-traded products like bond ETFs and gold ETFs do allow same-day trading, this applies equally to all eligible investors regardless of their trading method.

The so-called "synthetic T+0" strategy - where an investor buys and sells the same stock on the same day using existing holdings - is available to anyone, not just algorithmic traders. However, regulators have banned the use of securities lending for intraday round-trip trading since February 2024, and fully suspended stock borrowing for short selling since July 2024.

Rather than calling for a ban on algorithmic trading, experts advise retail investors to adapt their approach. Wang Han, Chief Global Economist at Industrial Securities, recommends three strategies: maintain rational investing by controlling emotions rather than focusing on market tools; adopt a long-term perspective to capture value from quality companies; and leverage professional institutions through regulated products like mutual funds.

The rise of AI large language models also poses new risks. Some social media posts have made incorrect claims about US market regulations, falsely stating that quantitative traders are limited to 15 orders per second and 15% cancellation rates. Galaxy Securities Chief Economist Zhang Jun warns that AI hallucinations can generate convincing but inaccurate answers about financial regulations, potentially misleading investors who rely on such tools for information.