作者：沉益勤几十年来，美国证券交易所每天晚上都会按下暂停按钮，导致市场关闭数小时。到了12月，随着股市转向全天候交易，灯光将持续更长时间。
For decades, US equity exchanges have hit the pause button every night, leaving markets shut for several hours. Come December, the lights will stay on much longer as the stock market shifts toward around-the-clock trading.
纳斯达克、纽约证券交易所Arca、24 X国家交易所和Cboe EDGX已制定计划，在常规营业时间和现有的市场前和市场后时段的基础上，在纽约增加晚上9点至凌晨4点的隔夜交易时段。此次扩张定于12月6日进行，旨在捕捉外国投资者不断增长的需求，同时与加密货币和预测市场竞争，后者颠覆了人们对华尔街营业时间的传统预期。
Nasdaq, NYSE Arca, 24X National Exchange and Cboe EDGX have crafted plans to add an overnight session from 9 p.m. to 4 a.m. in New York, on top of the regular hours and existing pre- and post-market periods they already operate. The expansion, set to take place on Dec. 6, seeks to capture growing demand from foreign investors while competing with crypto and prediction markets, which have upended traditional expectations of Wall Street’s operating hours.
隔夜交易已存在多年，主要通过替代交易系统，但隔夜交易只占总活动的一小部分--上周美国证券交易委员会圆桌会议上公布的数据显示，隔夜交易仅占第二季度股票交易量的1%左右。不过，尽管从任何角度来看，隔夜交易规模都仅次于日间交易，但隔夜交易增长迅速，比一年前飙升了358%。
Overnight trading has existed for years, primarily through alternative trading systems, but it’s made up a tiny slice of the total activity — around 1% of equity trading volume in the second quarter, data presented at a Securities and Exchange Commission roundtable last week show. But while tiny next to daytime trading by any account, overnight trading is growing quickly, surging 358% from a year ago.
23/5交易的预期实施引发了一场关于更长的工作时间对全球市场参与者意味着什么的争论。支持者表示，扩张将消除时区障碍，让外国贸易商更好地进入美国市场。怀疑论者认为，较低的流动性和更大的买卖价差放大了交易风险。
The anticipated implementation of 23/5 trading has sparked a debate about what longer hours would mean for market participants worldwide. Proponents say the expansion will remove time-zone barriers and give foreign traders better access to US markets. Skeptics see lower liquidity and wider bid-ask spreads as amplifying trading risks.
Crisil Coalition Greenwich高级分析师David Easthope表示，机构投资者主要担心“延长营业时间内的市场质量”，而对运营和人员配备的担忧不一定是他们的首要担忧。
Institutional investors are mainly worried “about the market quality during the extended hours,” said David Easthope, a senior analyst at Crisil Coalition Greenwich, while concerns about operations and staffing are not necessarily at the top of their list.
该公司去年对买方股票交易员进行的一项调查显示，市场参与者并不急于全天候交易股票。由于在正常时间以外活跃的参与者越来越少，投资者可能面临交易量下降、流动性下降和买卖价差扩大的局面。调查显示，这可能会带来额外的操作风险和复杂性，甚至影响交易员自身的身心健康。
A survey of buy-side equity traders the firm conducted last year showed market participants were not eager to trade stocks around the clock. With fewer players active outside regular hours, investors could face lower trading volumes, thinner liquidity and wider bid-ask spreads. That could bring additional operational risk and complexity, or even affect traders’ own physical and mental health, the survey showed.
自2025年下半年进行调查以来，该群体的情绪有所改善。伊斯特霍普表示，现在“有了更大的必然性”，特别是随着监管机构推进这些变化。
The group’s sentiment has somewhat improved since the survey was conducted in the second part of 2025. There’s now “a greater sense of inevitability,” particularly as regulators move forward with the changes, Easthope said.
多年来，隔夜交易的概念一直受到散户投资者和交易场所的欢迎。Blue Ocean Technology首席执行官Brian Hyndman表示，一旦12月的变化开始，“通常的嫌疑人就会出现并做好准备”，Blue Ocean Technology是目前促进隔夜交易的ATS提供商之一。
The concept of overnight trading has been popular with retail investors and trading venues for years. Once the December changes kick in, “the usual suspects will be there and be ready,” said Brian Hyndman, chief executive officer of Blue Ocean Technologies, one of the ATS providers that currently facilitate overnight trading.
“但我仍然认为我们缺少了该行业的一部分，那实际上是买方和投资银行，”他补充道。“他们一直犹豫是否参与其中。”主要市场基础设施提供商也在为这一转变做准备。存管信托与清算公司，负责清算美国股票交易的主要公司于6月份转向24 x5模式，从纽约时间周日晚上8点到纽约时间周五晚上8点。收集和分发报价和交易数据的证券信息处理器（CIP）也得到了监管机构的同意，延长营业时间以支持隔夜交易。
“But I still think that we’re missing part of the industry, and that’s really the buy side and the investment banks,” he added. “They’ve been hesitant to get involved.”Key market infrastructure providers are also preparing for the shift. Depository Trust & Clearing Corp., the main firm responsible for clearing US stock trades, in June moved to a 24x5 model running from 8 p.m. New York time on Sunday to 8 p.m. New York time on Friday. Securities Information Processors, or SIPs, which collect and distribute quotes and trade data, also got a regulatory nod to extend their operating hours to support overnight trading.
Themis Trading LLC合伙人兼股票交易联席主管Joseph Saluzzi表示，这一转变的支持者可能会押注于这样一种观点：一旦基础设施建成，机构需求就会随之而来。然而他对过渡持怀疑态度。
Proponents of the shift are likely betting on the idea that once the infrastructure is there, institutional demand will follow suit, said Joseph Saluzzi, partner and co-head of equity trading at Themis Trading LLC. Yet he’s skeptical about the transition.
他表示：“机构投资者对在流动性低、价差广泛的市场进行交易没有兴趣，该市场可能非常波动。”他补充说，交易所盘前和盘后交易量的总和仅占整体交易活动的10%左右。“实际上，如果你想成功的话，我们在市场上的时间太多了，而不是太少。”目前，机构投资者仍处于观望状态。Liquidnet市场结构主管杰夫·奥康纳（Jeff O ' Connor）表示，如果12月6日的转变改善了深夜的价格发现，交易成本最终将下降，帮助机构资金经理在夜间捕捉阿尔法。
“Institutional investors have no interest in trading in a low liquidity, wide-spread market which is likely to be very volatile,” he said, adding that the combined volume of pre- and post-market trading on the exchanges accounts for just about 10% of the overall trading activity. “There’s actually a case, if you wanted to make it, that we have too many hours in the market, not too few.”For now, institutional investors remain in wait and see mode. If the Dec. 6 shift improves price discovery during late hours, the cost of trading will eventually drop, helping institutional money managers capture alpha during the night, according to Jeff O’Connor, Liquidnet’s head of market structure.
当然，外国投资者在深夜尤其活跃。根据美国证券交易委员会的数据，它们占第二季度隔夜交易量的37%，而机构账户仅占7%。
Naturally, foreign investors are particularly active in late hours. They accounted for 37% of overnight trading volume in the second quarter, compared with just 7% for institutional accounts, according to the SEC data.
这种交易活动也高度集中。8月份，平均只有15只股票占隔夜总成交量的一半，其中通常包括位于中国和香港的公司的亚美元股。相比之下，256只股票占常规交易量的一半。
That trading activity is also highly concentrated. In August, just 15 stocks on average were responsible for half of the total overnight volume, often including sub-dollar shares of companies domiciled in China and Hong Kong. By contrast, 256 stocks accounting for half the volume during the regular session.
目前，纳斯达克和纽约证券交易所的核心交易时段为美国东部时间上午9：30至下午4点，每周五天。这些时间由交易前和交易后交易时段补充，允许最早从凌晨4点开始进行有限类型的交易，以及下午4点至晚上8点的盘后交易时段。12月扩张后，交易所仍将在晚上8点至晚上9点之间有一小时的休息时间，用于维护和交易处理。
For now, Nasdaq and NYSE operate core sessions from 9:30 a.m. to 4 p.m. ET, five days a week. Those hours are supplemented by before- and after-hours sessions allowing limited types of trading starting as early as 4 a.m. and a post-market session from 4 p.m. to 8 p.m. After the December expansion, the exchanges will still have a one-hour break from 8 p.m. to 9 p.m. for maintenance and trade processing.