The closing bell is becoming optional.

Avenir Technology · 9 min read

For a century, market risk had a rhythm, and that rhythm was the close. Mark positions to market at end of day, recalculate margin overnight, open again in the morning. Almost everything in post-trade risk, from variation margin to collateral cycles to participant monitoring, is built around that daily heartbeat.

The heartbeat is fading.

In 2025 the SEC approved 24X National Exchange, the first US national securities exchange cleared to trade 23 hours a day. In April 2026 it approved Nasdaq's move to a 23-hour, five-day schedule, following NYSE Arca down the same path. And from 28 June 2026, DTCC's NSCC, the central counterparty that guarantees US equity trades, begins clearing on a 24x5 cycle, from Sunday evening to Friday evening, extending its guarantee to overnight activity. Crypto has run around the clock for years. Tokenised securities and overnight retail demand are pulling traditional venues in the same direction.

When the day loses its edges

When the day no longer formally ends, "intraday" quietly loses its meaning. Intraday risk management was always defined against the close: the things you watch between this morning's open and tonight's settlement. Take away the close and you are left with one continuous tape of exposure, and a risk stack that still wants to chop it into days.

The infrastructure owners are saying this in plain language. DTCC's own paper on the shift to 24x5 is blunt: risk systems "must be adapted to function effectively overnight, with real-time and continuous monitoring and surveillance replacing batch-based routines," and it warns that "many existing risk platforms are not configured for near-continuous cycles." The World Federation of Exchanges points to a subtler hazard: extended trading can push activity "beyond the hours in which clearing, funding and payment systems are fully operational." In other words, exposure can build at 3am while the very machinery that would mobilise collateral to cover it is closed for the night.

The rulebook was built for a market that closes

The gap shows up in the rulebook too, not as a flaw but as the design of a different era. The global standard for CCP margining, the CPMI-IOSCO Principles, asks clearing houses to mark to market and collect variation margin "at least daily", with intraday calls layered on top, both scheduled and unscheduled. In practice that remains discrete. A 2024 survey found that roughly two-thirds of CCPs make at least one scheduled intraday margin call a day, some as many as five, and a third make none at all. Even the front-runners are bounded by office hours. NSCC will monitor exposures roughly every fifteen minutes. Eurex Clearing issues intraday margin calls only inside defined business hours. Five snapshots a day, or one every fifteen minutes inside a daytime window, is a genuine improvement on once a night. It is not the same as knowing where you stand at 4am on a Tuesday while an overnight session is moving against a participant.

You do not need a 24-hour market to have this problem

Here is the part that gets lost in the 24/7 headlines: you do not need a market that never closes to be exposed to this. The risk was never about the length of the trading day. It is about the gap between the moments you actually look. A venue that trades six hours and marks to market once a day carries the same blind spot as a 24-hour one. Exposure accumulates in between; you simply cannot see it. And the most violent risk events happen inside ordinary hours. When nickel prices on the London Metal Exchange nearly quadrupled over three trading days in March 2022, LME Clear faced around $19.7 billion in margin calls, enough to tip several clearing members into default, with a single account breach of $2.0 billion that on its own exceeded the entire $1.1 billion default fund. LME Clear was already calling variation margin every hour. Hourly was not enough when a concentrated position moved that fast.

If anything, the case for continuous risk is strongest in smaller and less mature markets, not weakest. CPMI-IOSCO's own data shows that roughly a third of clearing houses make no scheduled intraday margin call at all, relying on a single daily cycle. Those are rarely the deep, liquid, around-the-clock venues. They are the markets where liquidity is thin, a handful of participants dominate, and one name moving can threaten the whole book, which is exactly where a once-a-day snapshot is most dangerous. Seeing exposure, margin and collateral as a live picture pays for itself immediately there: earlier warning of a deteriorating member, tighter and fairer collateral calls, live visibility for participants, and a default-management process that starts from an accurate position rather than last night's batch. None of that requires extending your trading hours by a single minute. And risk does not keep market hours anyway: positions carry overnight, collateral and currencies revalue, corporate actions land, all while the local market is dark.

Continuous, not faster intraday

This is why the most credible label for where risk management is heading is not "faster intraday". It is continuous. Continuous risk management means treating exposure, margin, collateral and participant risk as a live state that is always current, rather than a report you rebuild at intervals. The leading vendors have already moved their language here. Sterling Trading Tech brands its platform a "Real-Time Risk Management System". Nasdaq markets its clearing technology around "real-time margining" and titles its account of the transition "From End-of-Day to Always-On". The category is forming, and "intraday" is not the word the market is reaching for to describe the destination.

What continuous does and does not mean

A word of caution, because it is the part most people get wrong. Continuous does not have to mean recalculating every participant's margin every millisecond, and the regulators are careful here. The Bank of England, drafting new guidance for clearing houses, says continuous monitoring "can be achieved through predefined thresholds and alerts" and explicitly "does not require continuous calculation of initial and variation margin". The right reading is not "compute everything constantly". It is "always know where you stand, and act the instant a threshold is crossed, whatever the hour". Continuous monitoring, with intelligent, event-driven recalculation, rather than brute force.

Intraday is the on-ramp. Continuous is the trajectory.

So the honest position is not that "intraday" is wrong. It is the on-ramp. It is the language of the market as it operates today, and it still belongs in every conversation with a clearing house running scheduled calls inside business hours. Continuous is the trajectory. It is the language of the market that 24X, Nasdaq, NSCC and the tokenisation crowd are busy building. The exchanges, depositories and clearing houses that come through around-the-clock trading in good shape will be the ones who chose their risk infrastructure for the second picture while they still operated in the first.

That matters as much in growth markets as in New York or London, and you do not have to be anywhere near 24/7 to act on it. An exchange, CSD or clearing house modernising today is choosing a platform it will run for the next decade or more. A continuous risk layer earns its place from day one in a market that trades a few hours a day, through earlier detection, better collateral efficiency and live participant visibility, and it compounds as and when you extend hours. Building the risk layer for a world that only exists between 10am and 4pm is the expensive mistake, whether or not you ever ring a bell at midnight.

The question to ask your risk stack

If you run an exchange, a CSD or a clearing house, the question to put to your risk stack is simple. When trading does not stop, does your view of risk stop with it? If your margin engine, your collateral management and your participant monitoring fall quiet between a late session and the next morning's batch, you are carrying an exposure window that widens every time the market extends its hours. Closing that window, rather than buying a faster overnight job, is the real work of the next few years.

At Avenir Technology we are building AvenirRisk around exactly that idea: continuous visibility of exposure, margin, collateral and participant risk across the clearing and settlement chain, designed for markets where the close is becoming optional. The bell may keep ringing for the sake of tradition. Your risk framework should stop depending on it.

Originally published on LinkedIn.

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