The race to bring near-24-hour trading to the U.S. stock market is accelerating across Wall Street, but the biggest obstacle is no longer regulatory approval — it is the aging infrastructure underneath the American financial system itself.
Major exchanges including Nasdaq, NYSE Arca, and startup venue 24X National Exchange have now secured key approvals from the U.S. Securities and Exchange Commission to operate extended overnight trading sessions, marking one of the most significant structural changes to U.S. equity markets in decades. Yet despite the approvals, the market’s core data and clearing systems remain unable to fully support round-the-clock trading, creating a bottleneck that is forcing billions of dollars of overnight activity into lightly regulated alternative venues.
The tension is quickly becoming one of the defining market-structure battles facing SEC Chairman Paul Atkins, whose deregulatory agenda has prioritized modernization efforts across U.S. capital markets.
“The global demand for U.S. equities does not stop when the traditional trading day ends, and neither should the protections of a regulated national securities exchange,” Dmitri Galinov, founder and chief executive of 24X National Exchange, wrote in an April 29 letter to the SEC requesting temporary relief allowing the exchange to begin full overnight operations before industry systems are fully upgraded.
The request highlights the core problem confronting the industry: exchanges may be ready for overnight trading, but the underlying “plumbing” of the National Market System is not.
At the center of the delay are the market’s Securities Information Processors (SIPs) — the systems responsible for consolidating and distributing real-time stock quotes and transaction data across U.S. exchanges. Those systems currently do not operate on a 23-hour schedule, preventing exchanges from fully launching overnight sessions even after winning regulatory approval.
Industry operators now estimate the upgrades will not be completed until late 2026.
The SEC has already approved 23-hour weekday trading sessions for three venues:
- 24X National Exchange
- NYSE Arca
- Nasdaq
Nasdaq’s proposal received accelerated SEC approval on April 10 after initially being filed in December 2025. Additional filings from Cboe Global Markets and MEMX are widely expected next, according to the Securities Industry and Financial Markets Association (SIFMA).
The momentum reflects a rapidly changing investor landscape driven by global retail trading, international demand for U.S. equities, and the growing expectation that financial markets should function continuously in an increasingly digital economy.
But while exchanges await infrastructure upgrades, overnight trading activity has already exploded elsewhere.
The dominant venue today is Blue Ocean ATS, an alternative trading system handling overnight orders for firms including Robinhood Markets and Charles Schwab. According to company figures, Blue Ocean processed approximately $374.7 billion in notional overnight trading volume across 307 sessions in 2025 — averaging roughly $1.22 billion per night.
Industry forecasts suggest overnight trading could eventually represent between 5% and 10% of total U.S. equity activity.
Still, the market remains relatively small compared with traditional daytime trading and carries significant risks.
Blue Ocean suffered a major outage in August 2024 that reportedly canceled approximately 464 million orders affecting roughly 90,000 accounts, triggering backlash from South Korean brokerages and exposing concerns about the resilience of overnight market infrastructure. Competitors including Bruce ATS and Moon ATS later entered the space.
Independent data from BMLL Data Lab show overnight trading still accounts for only about 11 basis points of total U.S. equity notional volume once all trading sessions are included — evidence of rapid growth, but still a tiny share of the broader market.
Institutional investors remain cautious.
Kenji Takeda, head of equity trading at Nomura Asset Management in Tokyo, warned that liquidity remains too thin for large-scale institutional participation.
The concern is straightforward: expanding trading hours without sufficient participation risks wider bid-ask spreads, weaker price discovery, and heightened volatility during periods with reduced staffing among market-makers, compliance teams, and risk managers.
Current overnight trading remains heavily retail-driven. Blue Ocean estimates roughly 90% of overnight volume comes from retail investors, supported by a small group of approximately ten market-makers providing liquidity.
For Chairman Atkins, the debate now centers on whether the SEC should temporarily allow exchanges like 24X to operate overnight before the SIP systems are fully upgraded.
Supporters argue that regulated exchanges provide greater transparency and investor protections than alternative trading systems already dominating the overnight market.
Critics warn that allowing exchanges to bypass the consolidated public data framework — even temporarily — risks undermining the very foundation of the National Market System established by Congress in 1975.
The decision could reshape the structure of U.S. markets for decades.
If approved, overnight exchange trading would represent one of the largest operational shifts on Wall Street since the transition to electronic markets. It would also further blur the distinction between U.S. trading hours and global markets, allowing investors in Asia, Europe, and the Middle East to participate in American equities nearly continuously.
The question now facing regulators is no longer whether overnight trading is coming.
It is whether the infrastructure powering the world’s largest capital markets can evolve fast enough to keep up.
JBizNews Desk
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