Direct Answer
The halt and volatility control explorer looks up how Limit Up-Limit Down (LULD) price bands, market-wide circuit breakers, and single-stock halts apply to a given scenario. It calculates the applicable price band, identifies the relevant circuit breaker threshold, and explains what happens to open orders during each halt type.
Halt & Volatility Control Explorer
Explore how LULD price bands, market-wide circuit breakers, and single-stock halts work. Calculate price bands, look up circuit breaker thresholds, and understand what happens to open orders during any halt type.
Educational tool only. All figures are based on publicly documented regulatory rules (SEC, FINRA, SRO plan). Thresholds can change; verify against current exchange and SRO publications before making trading decisions. This tool does not constitute investment advice.
Volatility Control Explorer
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The Limit Up-Limit Down (LULD) plan sets a price band around each NMS stock's reference price. Trades outside the band are prevented; if the national best bid sits at the upper band or the national best offer sits at the lower band (a limit state) and is not executed or cancelled within 15 seconds, a 5-minute trading pause is triggered.
LULD Band percentage reference
| Price range | Tier 1 (core session) | Tier 2 (core session) | Last 25 minutes (3:35 PM to 4:00 PM) |
|---|---|---|---|
| > $3.00 | 5% | 10% | Tier 1 10%; Tier 2 10% (not doubled) |
| $0.75, $3.00 | 20% | 20% | Doubled (40% / 40%) |
| < $0.75 | Lesser of $0.15 or 75% | Lesser of $0.15 or 75% | Doubled |
Bands are calculated from the average price of eligible trades over the preceding five minutes; the first reference price of the day is the primary listing exchange's opening price. Unleveraged ETPs, including inverse ETPs, with more than $2,000,000 of average daily notional volume are generally Tier 1. Leveraged ETPs are Tier 2, and their bands are the Tier 2 percentage multiplied by the leverage ratio.
Market-wide circuit breakers (Rule 80B) halt all U.S. equity trading when the S&P 500 drops a defined percentage from the prior day's close. Three levels exist; Level 3 halts trading for the rest of the day regardless of when it triggers.
Scenario lookup
All three levels at a glance
| Level | S&P 500 decline | Before 3:25 PM, halt duration | At or after 3:25 PM |
|---|---|---|---|
| Level 1 | 7% | 15 minutes, then reopens | No halt, trading continues |
| Level 2 | 13% | 15 minutes, then reopens | No halt, trading continues |
| Level 3 | 20% | Halt for remainder of day | Halt for remainder of day |
Each level can only be triggered once per day. A Level 1 halt that has already been triggered does not halt again even if the market falls to the Level 1 threshold a second time, trading continues until Level 2 is breached. Thresholds are set using prior-day close and published by the exchanges each morning before the open.
Single-stock halts fall into three broad families: regulatory (exchange or regulator-initiated), news-pending (Nasdaq/NYSE), and volatility-driven (LULD pause or exchange-specific). Click a halt type to see its trigger, duration, and what happens to open orders.
What happens to your open orders when a halt is triggered depends on the halt type, your order type, and where the order was resting. Use this lookup to understand the likely outcome for common scenarios.
Frequently Asked Questions
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An LULD (Limit Up-Limit Down) pause is a 5-minute halt declared by the primary listing exchange when the national best bid stays at the upper price band, or the national best offer stays at the lower price band, for 15 seconds without being executed or cancelled. It is mechanical, no human decision-maker initiates it. The pause ends automatically after 5 minutes and the stock reopens via an auction.
A regulatory halt is initiated by a regulator (SEC, FINRA) or a listing exchange. It can last from minutes to days and is typically tied to a specific event: material news pending, a trading investigation, or failure to meet listing standards. Regulatory halts require an explicit lift before the stock can trade again.
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For Level 1 and Level 2 circuit breakers, no, they do not halt trading if triggered at or after 3:25 PM ET. The intent is to avoid disrupting the closing auction process when the trading day is nearly over.
Level 3 (a 20% decline in the S&P 500) is the exception: it halts trading for the remainder of the day regardless of when it is triggered. This has never been triggered since the modern rule took effect in 2013, the steepest single-day declines since then remained below 13%.
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If your market order reached the exchange before the pause began and was not yet filled, it typically remains open in the order book during the 5-minute pause. When trading resumes, LULD pauses reopen through an auction process. Your market order would execute at the auction-clearing price, which may be meaningfully different from the pre-halt reference price, particularly if the fundamental cause of the movement persists.
If your market order was submitted to your broker but had not yet been routed to the exchange when the halt was declared. The broker may queue it or route it when trading resumes. Check your broker's specific handling policy; some brokers convert unrouted market orders during halts to limit orders to prevent extreme execution prices.
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The LULD plan applies during the regular trading session (9:30 AM, 4:00 PM ET) only. Extended-hours trading (pre-market and after-hours) on ECNs is not covered by LULD. This means stocks can trade at prices outside what would be their LULD band during those sessions, extremely wide bid-ask spreads and thin liquidity make extended-hours prices much more volatile in practice.
Market-wide circuit breakers similarly apply only during regular session hours.
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For stocks priced below $0.75, the LULD band uses whichever is smaller: $0.15 or 75% of the reference price. This prevents the percentage-based formula from producing absurdly wide bands on penny stocks while still capping extreme moves.
For stocks priced between $0.75 and $3.00, a flat 20% band applies regardless of tier. The 5% (Tier 1) or 10% (Tier 2) percentage bands only kick in for stocks priced above $3.00. During the last 25 minutes of the session (3:35 PM to 4:00 PM ET, or the last 25 minutes before an early scheduled close), bands are doubled for all Tier 1 stocks and for Tier 2 stocks priced at or below $3.00; Tier 2 stocks above $3.00 keep their 10% band.
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No, when a stock is halted, all U.S. exchanges and ATS venues that disseminate quotes and facilitate trading in that NMS security are required to honor the halt. The halt is disseminated through the Consolidated Tape and the SIP (Securities Information Processor), and all trading venues must stop accepting executable orders in the halted security until the halt is lifted.
However, broker-to-broker negotiated transactions (OTC trades not going through lit exchanges) may technically occur in some circumstances, but these are rare, non-standard, and may face regulatory scrutiny. For all practical purposes, a halt means no trading anywhere in the U.S. until it is lifted.
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A straddle state occurs when the national best bid is below the lower LULD band, or the national best offer is above the upper band, while the stock is not in a limit state. The LULD plan does not make a straddle state trigger a pause automatically; it allows the primary listing exchange to declare a trading pause when a stock in a straddle state is trading in a way that departs from normal trading characteristics, under the exchange's own policies.
For traders, the straddle state is a warning sign: liquidity has dried up to the point that one side of the quote sits outside the permitted range. Prices on resumption may gap significantly once normal quoting resumes.
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The price-band framework operates under a national market system plan filed with and approved by the regulator, and the plan document sets out the tiers, band percentages, the widening near the close and the pause procedure. Market-wide circuit breakers operate under exchange rules approved the same way. Those filings are the authoritative text; explanations elsewhere, including this page, summarize them and can lag amendments.
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The questions worth answering before the fact are whether the security is in a tier with wider or narrower bands, whether the intended exit relies on a resting order that a pause would leave unfilled, and how much of the position could be exited within a single session under normal conditions. Deciding the response while trading is halted is the situation these mechanisms are most likely to create.
References
Related lessons
- Limit Up-Limit Down (LULD) Trading Pauses Explained
- Market-Wide Circuit Breakers Explained
- Single-Stock Halts: News, Volatility, and Regulatory Pauses
- Opening Auctions: How the First Price Is Formed
- Common Extended-Hours and Halt-Related Mistakes
- Stop, Stop-Limit, and Triggered Orders in Real Markets
- Auction Imbalances and Indicative Prices