A-Share Market Upgrades: Expanded Post-Market Trading and Enhanced Market Making

“Addressing Institutional Gaps” and “Stabilizing Capital Inflows”: The Underlying Logic of A-Share Trading Mechanism’s Systemic Upgrade

Recently, the Shanghai and Shenzhen Stock Exchanges have rolled out a series of trading mechanism optimizations in rapid succession—marking the entry of A-share investment-side reform into a substantive, pivotal phase. The Shanghai Stock Exchange (SSE) has extended the Post-Market Fixed-Price Trading (PFC) mechanism from the STAR Market to all A-share stocks and ETFs; concurrently, the Shenzhen Stock Exchange (SZSE) is expanding the market-making system on the ChiNext, piloting post-market ETF trading, introducing real-time confirmation for negotiated block trades, and refining the criteria for identifying strategic investors. These measures are not isolated technical tweaks but rather a cohesive, systemic institutional package, precisely calibrated to resolve core pain points confronting long-term capital. At its essence, this reform reconstructs the liquidity ecosystem at the foundational institutional level—establishing more efficient, predictable, and lower-friction on-ramps for allocation-oriented investors such as insurance funds, pension funds, and public mutual fund-of-funds (FOFs), all of whom prioritize stable returns and low execution costs.

Full Coverage of Post-Market Fixed-Price Trading: Extending the Price Discovery Chain and Mitigating Large-Order Impact

The SSE’s extension of the PFC mechanism to all A-share stocks and ETFs represents the most emblematic breakthrough of this round of reform. Previously available only on the STAR Market, PFC primarily served institutional investors seeking large-volume, low-impact transactions executed at the closing price. What value does its expansion across the entire market deliver? Its significance lies in the synergistic convergence of three key effects: time extension, impact attenuation, and expectation reinforcement.

First, PFC extends the effective trading window by five minutes—from 15:00 (the official close) to 15:05—providing institutions with a critical buffer period for end-of-day portfolio rebalancing, index reconstitution, or responding to sudden events. This is especially vital for broad-based ETFs, whose creation/redemption requires real-time matching against a basket of underlying stocks. If constituent stocks experience sharp, illiquidity-driven gaps during the final moments of continuous auction trading, it directly widens the ETF’s indicative optimized portfolio value (IOPV) deviation and inflates arbitrage costs. By executing at the official closing price, PFC eliminates this uncertainty.

Second, large buy/sell orders in continuous auction trading often trigger sharp price volatility. PFC, however, matches orders based on the closing price, applying time-priority and then quantity-priority rules—naturally avoiding instantaneous price impact during the price discovery process. For insurance funds and other participants routinely executing multi-hundred-million-RMB trades, this significantly lowers execution costs. Brokerage estimates suggest that applying PFC to CSI 300 constituents could reduce average impact cost by 30%–50%.

Third, universal application of PFC across the market strengthens the consensus that the “closing price equals fair value,” enhancing the authority and stability of this key price signal—and providing a more robust anchor for derivatives pricing, performance benchmark calculation, and other critical functions.

Dual Upgrades: ChiNext Market Making & ETF Mechanisms — Building a Multi-Tiered Liquidity Support Network

The SZSE’s enhancements to the ChiNext focus on deepening resilience and liquidity in this dynamic, growth-oriented segment. First, it expands the scope of market makers and refines their incentive and accountability frameworks—not limiting participation to top-tier brokers but enabling more institutions with proven risk control and pricing capabilities to join. Through continuous two-way quoting, market makers effectively narrow bid-ask spreads. In the ChiNext—where liquidity is highly fragmented across stocks—this creates an “invisible liquidity pool” for small- and mid-cap technology firms. Data shows that the first batch of ChiNext ETFs under market making achieved an average daily bid-ask spread of just 0.08%, 42% tighter than non-market-made ETFs.

Second, post-market ETF trading and real-time confirmation for negotiated block trades operate in complementary fashion: the former meets institutional demand for precise, targeted ETF allocation; the latter reduces the settlement timeline for negotiated block trades from T+1 to instantaneous, dramatically improving operational efficiency for strategic placements, private placement share reductions, and similar scenarios. Coupled with refined criteria for strategic investors—explicitly emphasizing substantive requirements such as long-term holding and active corporate governance participation—the policy actively steers capital away from short-term speculation toward long-term alignment—a shift deeply resonant with China’s drive to cultivate “new-quality productive forces.”

The Foundational Logic of Investment-Side Reform: From “Attracting Capital” to “Retaining Capital”

These coordinated adjustments must be understood within the China Securities Regulatory Commission’s (CSRC) overarching framework of “strengthening regulation, preventing risks, and promoting development.” Over the past decade, A-share financing-side reforms have yielded remarkable results—but investment-side institutional development has lagged, resulting in long-term capital remaining hesitant to enter (“willing but afraid”) or failing to stay once it does (“entered but didn’t remain”). This round of mechanism optimization directly targets three fundamental bottlenecks: liquidity stratification, prohibitively high execution costs, and temporal misalignment between investor needs and market infrastructure.

Critically, the reform forms a virtuous cycle with improvements in listed-company quality. The SZSE’s fourth listing standard emphasizes “expected market cap + revenue + compound growth rate”; the Ministry of Finance has imposed strict penalties on auditing firms found negligent; and the CSRC is coordinating with local governments to channel high-quality science-and-tech enterprises into the market. Collectively, these initiatives aim squarely at elevating asset quality at the source. When high-caliber assets meet efficient, low-cost trading infrastructure, the A-share market can truly evolve from merely “attracting capital inflows” to genuinely “anchoring long-term capital.”

Multi-Dimensional Beneficiaries: Synchronized Gains for Broad-Based ETFs, Leading Brokers, and Tech Enablers

Institutional dividends will accrue most rapidly to three categories of participants.

• Broad-based ETFs, as the core vehicles for long-term capital, will see markedly improved tracking accuracy and creation/redemption efficiency—driving accelerated scale expansion—thanks to full PFC coverage and enhanced market-making support.
• Leading securities firms with comprehensive licenses and strong market-making capabilities (e.g., CITIC Securities, China International Capital Corporation [CICC], Huatai Securities) stand to gain incremental revenue from market-making spreads, ETF market-making commissions, and system services for block trades.
• Trading-system technology providers (e.g., Hundsun Technologies, Dingdian Software) benefit from rigid demand stemming from exchange interface upgrades, market-making algorithm enhancements, and post-market trading module development—boosting both order volume and average contract value.

This quiet yet profound transformation of A-share trading mechanisms transcends mere technical parameter adjustments. It signals a pivotal shift in the market’s developmental focus—from the regulatory paradigm of “building institutions, non-intervention, zero tolerance,” toward a new stage centered on “optimizing mechanisms, strengthening services, and facilitating allocation.” When the closing price ceases to be merely the endpoint of trading and instead becomes a stable, all-day anchor for price discovery; when the ChiNext sheds its label as a “high-risk zone” to emerge as a growth engine safeguarded by professional market makers; when a RMB 1-billion allocation instruction can be executed smoothly and predictably within five minutes—at that moment, long-term capital’s “psychological anchor” is truly secured. This is not just about raising trading efficiency; it marks a decisive step forward in China’s capital markets’ evolution—from a “financing market” to an “investment market.”