CIRO proposes extended-hours volatility controls with a closing-period exception

Canada’s investment industry regulator has proposed extending volatility controls into trading sessions before the equity market opens and after it closes. CIRO’s 13 October consultation covers marketplaces for which it provides regulation services, with comments due on 12 November. The changes remain proposals.[1]

The proposal follows CIRO’s 8 October warning that longer trading hours can bring thinner liquidity, wider spreads and sharper reactions to news. These conditions matter particularly when earnings or other announcements arrive outside the regular session: access to a market does not ensure the same depth of trading interest.[5]

Two controls with different effects

Marketplace thresholds prevent an incoming order from executing beyond prescribed price limits. Single-stock circuit breakers, or SSCBs, pause trading in an eligible security after a sufficiently large, rapid move.[2][3]

Today, marketplace thresholds apply from 9:30 a.m. to 4 p.m. Eastern Time and SSCBs from 9:30 a.m. to 3:30 p.m.[1]

SSCBs would be switched off from 3:30 to 4:15 p.m. to avoid disrupting the closing price. Marketplace price thresholds would continue, and CIRO would retain its discretionary halting powers. Threshold levels would initially stay unchanged while CIRO gathers trading data. Trading before 7 a.m. or after 8 p.m. would require a further framework review.[1][2][3]

The draft provides an initial five-minute halt, which may be extended by another five minutes. The wider post-halt trigger applies during the first 30 minutes after trading resumes, including after an SSCB halt.[3]

The draft does not apply SSCBs to every listed security. Coverage includes the S&P/TSX Composite constituents, qualifying ETFs and Canadian depositary receipts, and securities meeting its active-trading criteria. If there has been no trade in the previous five minutes, the next trade establishes a reference price rather than triggering an SSCB.[3]

The opening auction changes the reference price

Under the threshold draft, continuous trading from 7 a.m. to 8 p.m. would be tested against two prices: the national last sale and its value at the start of the current minute. The first trade of the day establishes the starting price and is exempt; the previous day’s close is not carried forward for this calculation.[2]

A pre-market trade can leave that one-minute reference far from the opening-auction price. Without a reset, an order close to the auction price could be blocked by a limit calculated from earlier trading. The draft would therefore reset the one-minute reference when the primary listing exchange’s opening trade occurs. Opening orders themselves remain exempt from these thresholds.[2]

Dealer obligations already apply outside core hours

Separate dealer guidance published on 8 October says firms offering extended sessions remain responsible for supervision and best execution. It calls for disclosures explaining available venues, order handling and differences from the regular session. Firms are not required to offer extended-hours access and may restrict order types.[4]

That guidance also highlights a limit to the support available during longer sessions: exemption and rule-interpretation requests made outside CIRO’s normal 8 a.m.–5 p.m. business hours are handled on a best-efforts basis and generally will not receive real-time review. Longer access therefore brings operational questions beyond the exchange’s ability to accept an order.[4]

CIRO targets final guidance for January 2027, followed by 120 days before implementation; it does not expect implementation before May. The timetable and parameters remain subject to consultation.[1]

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