Trading Halt

Trading halts serve as a circuit breaker for individual stocks and, in some cases, for entire U.S. equity markets. They are designed to prevent panic-driven price moves from spiraling into disorderly markets where prices detach completely from fundamental value. In the United States, trading halts are overseen by FINRA, the SEC, and the individual exchanges — NYSE and NASDAQ — each of which has the authority to impose halts under specific circumstances.

Individual stock halts fall into several categories. A 'Regulatory Halt' (Halt Code T1 or similar) is imposed when a listed company is about to release material news — typically an earnings announcement, a significant acquisition, or a major regulatory decision — and the exchange wants to pause trading to allow that information to disseminate to all market participants simultaneously before prices begin to move. Companies can request a voluntary regulatory halt before releasing a press release. The halt typically lasts 30 to 60 minutes.

A 'Volatility Trading Pause' (VTP) is triggered when an individual stock's price moves up or down by 10% or more within a five-minute period. This is part of the SEC's Limit Up-Limit Down (LULD) plan, implemented after the May 6, 2010 Flash Crash in which the Dow Jones Industrial Average briefly plunged nearly 1,000 points in minutes partly due to cascading automated sell orders. The LULD mechanism sets price bands around each stock's recent average price; if a trade occurs outside those bands (or no trades occur because there are only offers above or only bids below the bands), a five-minute pause is triggered, giving the market time to reset.

Market-wide circuit breakers — formally called Market Wide Circuit Breakers (MWCBs) — pause all trading across U.S. equity and equity futures markets when the S&P 500 falls 7% (Level 1), 13% (Level 2), or 20% (Level 3) from the prior day's close. Level 1 and Level 2 halts last 15 minutes if triggered before 3:25 p.m. ET; a Level 3 halt closes markets for the day. These were triggered on March 9, 12, and 16, 2020, during the COVID-19 market panic — the first time MWCBs had been triggered in their modern form. NYSE specialists and DMMs play a key role in the reopening process after a halt, conducting an auction to find a new clearing price.

For investors, the practical impact of a trading halt is that outstanding orders may not be executed until the halt is lifted, and the price at which those orders execute can differ significantly from the pre-halt price. Investors should be cautious about placing market orders immediately after a halt is lifted, as opening prices can be volatile. Following a halt-and-resume, it is generally better to observe the price action for the first few minutes before executing to get a clearer sense of where the market is settling.