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Options Stopped Keeping Office Hours: Cboe's Extended Single-Stock Session, Cboe Predicts, And 23x5 Equities In December

Since 13 July, around twenty of the most-traded single-stock options - Nvidia, Tesla, Apple, Palantir, Broadcom, AMD among them - have traded on Cboe from 7:30am and until 4:15pm ET, the first time US equity options have escaped the regular session. In June the exchange announced Cboe Predicts, a regulated suite of yes-or-no binary contracts on the Mini S&P 500, cleared through the OCC and distributed by Interactive Brokers and Schwab. And in December, pending approval, Cboe EDGX joins Nasdaq in running US equities 23 hours a day. Three moves, one direction: derivatives are becoming continuous and retail-scale at the same time. For anyone building trading platforms, charting or risk systems, the assumptions that just expired are not the ones in the marketing.

AlchmAI Editorial12 min read

13 July

Extended hours began on Cboe Options for ~20 single-stock names: 7:30-9:25am and 4:00-4:15pm ET, Monday to Friday

$50bn

Minimum underlying market cap for eligibility, alongside 150,000+ options ADV and 10m+ shares ADV over six months

1/10

Cboe Predicts binaries are sized on the Mini S&P 500 (XSP) at a tenth of SPX, cleared through the OCC like any listed option

Dec 2026

Target for 23x5 US equities on Cboe EDGX, pending regulatory approval and industry readiness - alongside Nasdaq's 6 December launch

The equity market's move toward round-the-clock trading has had most of the attention this year, and rightly - Nasdaq's 23-hour day starts on 6 December and we have written about what it breaks. But the derivatives side has been moving in the same direction with less noise, and for platform builders it is arguably the harder change, because an option's value depends on time in a way a share price does not. Three Cboe developments in the past four months make the direction unmistakable.

First, extended hours for single-stock options. Following SEC approval announced on 28 May, Cboe Options began offering trading in around twenty multi-listed single-name options from 13 July: a pre-market session from 7:30am to 9:25am ET and a post-market session from 4:00pm to 4:15pm. The names are the ones you would guess - the Magnificent Seven including Nvidia, Tesla and Apple, plus Palantir, Broadcom and AMD - and eligibility is strict: 150,000-plus average daily options volume, a $50bn-plus underlying market cap and 10 million-plus shares traded daily, all measured over the preceding six months. Meaghan Dugan, Cboe's head of US derivatives, described the small initial list as a deliberately measured approach to keep market safeguards and investor protections in place. Cboe already runs near-24x5 trading in its proprietary index options - SPX, VIX, XSP and RUT - through Global Trading Hours and a curb session; this is the first time the model has reached single stocks.

Why Options Are Harder Than Stocks To Run Around The Clock

A share that trades at 8am has a price. An option that trades at 8am has a price, an implied volatility, a set of Greeks, and a time-to-expiry that every one of those numbers depends on - and the conventions for all of them assume a trading day with a defined open and close. Extended hours do not merely add time to the session. They change what the numbers mean.

  1. 01Theta stops being a daily quantity. Time decay is quoted per calendar day and computed against an expiry defined at a specific time. When the option trades before the underlying's regular session opens, models that count trading days versus calendar days, or that assume the day's decay is realised at the close, produce inconsistent values between the pre-market and the regular session.
  2. 02Implied volatility in thin sessions is not comparable to implied volatility in the day. A pre-market quote at 7:45am on an illiquid strike carries a wider bid-ask and less information than the 10am print, but a surface that ingests both without weighting will let the thin quote distort the whole curve. Every volatility surface and every Greeks dashboard now needs a session-aware quality filter.
  3. 03The underlying's reference price is ambiguous. A single-stock option trading at 8am references a share that may itself be trading in a thin pre-market, or may reference the prior close. Which one your pricing engine uses is a policy decision that has to be made explicitly and applied consistently, or your implied vol and your delta will disagree with your counterparty's.
  4. 04Margin and risk recalculation lose their quiet window. The overnight batch that recomputed portfolio Greeks assumed nothing moved between 4:15pm and the next open. It now moves, and a book that changed materially at 8am is carrying risk numbers from yesterday's close until the next run.
  5. 05Corporate actions and expiries collide with live sessions. Adjusting strikes for a split, or handling an expiry that lands inside an extended session, were overnight jobs. They now have to be sequenced against live quoting, exactly as on the equity side but with the added complication that the adjustment changes the option's economics, not just its label.

Cboe Predicts Is A Charting Problem Nobody Has Solved Yet

The binary contracts deserve a paragraph of their own because they do not fit the visualisations trading platforms already have. A vanilla option's payoff is a hockey stick; a binary's is a step. Its price is, in effect, a probability, and it moves in a way that looks nothing like a candlestick chart of the underlying. Platforms that render Cboe Predicts contracts using their existing options chain will produce something technically correct and practically unreadable.

The product also arrives with a specific retail intent - Cboe has tied it to XSP at a tenth of SPX size precisely to appeal to active retail users on Interactive Brokers and Schwab - which means the interface has to explain a probability-priced instrument to someone who has never traded one, inside a regulated options framework that requires suitability and disclosure. That is a design problem before it is an engineering one, and the platforms that get it right will be the ones that render the contract as what it is: a price for an outcome, with the implied probability, the time remaining and the settlement rule visible at a glance.

“The exchanges have made derivatives continuous and retail-scale in the same year. The platforms now have to make them legible at 7:30am to someone with a phone, which is a considerably harder problem than making them tradeable.”

What Platform And Risk Teams Should Do Before December

  1. 01Make the session calendar an authoritative service, for options as well as equities. Which instruments trade in which session on which dates, with which reference price - one source, queried by every system. Three exchanges are now extending hours on three different timetables, and Cboe's own list of eligible names will grow. Hardcoding any of it means doing the work again each time.
  2. 02Decide, in writing, what the reference price and time-to-expiry are in each session, and apply the same rule in pricing, risk and charting. Inconsistency between those three is the bug your traders will find first.
  3. 03Add a session-quality dimension to your volatility surface. Weight or exclude thin-session quotes explicitly rather than letting them contaminate the day's curve.
  4. 04Move Greeks and margin from overnight batch to incremental recalculation, or at minimum trigger a recalculation at the start of each extended session. Yesterday's delta at 8am is not a control.
  5. 05Design the binary-contract view before you list the product. A probability, a countdown and a settlement rule, rendered as such. Do not ship a hockey-stick chart for a step-function payoff.
  6. 06Test against a real extended-session tape. The 13 July onward data for the twenty eligible names is the replay set. Synthetic data will not reproduce the thin-quote and gap behaviour that actually causes problems.

The Bottom Line

In four months Cboe has taken single-stock options into pre- and post-market sessions for the twenty most liquid names, announced a regulated binary-contract suite on XSP aimed squarely at retail, and set a December date for 23x5 equities on EDGX to match Nasdaq. The direction is not in doubt: derivatives are becoming continuous and small-sized at the same time, and every assumption a platform made about a defined open and close - for theta, for the volatility surface, for the reference price, for margin, for the overnight batch - has quietly expired. The fixes are specific and mostly unglamorous: a single session calendar, an explicit reference-price policy, session-aware surface construction, incremental risk, a purpose-built view for step-function payoffs, and automated coverage for hours no desk can staff. That is the trading platform and charting work we do in London, and the exchanges have just moved the deadline forward to December.

References & Further Reading

Trading Platform DevelopmentHigh-Frequency Charting SolutionsReal-Time Data Ingestion & Plottingoptions market structureTrading Workflow automationInvestment Banking Trading ApplicationsCboe
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AlchmAI Editorial

Research and analysis, London

The AlchmAI team writes about the markets, technology and regulation we work with every day. We build trading platforms, real-time charts and AI analysis tools for brokers, prop firms and fintech teams from our office in Mayfair, London. Every article lists its sources. Nothing we publish is investment advice.

This article is general information and commentary. It is not investment advice or a recommendation to buy or sell any investment. Important information

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