Halt resumption: the reopening auction and the range of first prints
A halt ends in a reopening auction whose indicative price can move until the print. The first trade can land far from the halt price in either direction, and a stop cannot execute until it does.
Start in plain English
Small caps halt often: volatility pauses when price hits a LULD band, news-pending halts, and occasionally regulatory halts. For a scalper, the dangerous moment is not the halt itself but the resumption, when trading restarts at one auction price that can be far from where it stopped.
The core idea: a halt ends in a reopening auction, and its first print can land well above or well below the halt price. During the halt, nothing trades, so no stop can execute. When trading resumes, a triggered stop fills at the next available price after the auction. The indicative price shown during the halt is a snapshot of the auction book and can move until the print.
Halt codes and the general rules are covered in FennEdge's articles on trading halts and limit up / limit down (LULD), and in the US Day Trading Fundamentals lesson What happens to orders during a halt. This lesson covers the reopening process and the spread of first prints.
Two paths from the same start
All prices, sizes and messages in this example are Illustrative. Velloran Genomics is fictional and Nasdaq-listed.
The setup at 10:18:30 ET. Velloran ran from $4.10 to $4.62 in four minutes. At 10:14 it reached its upper LULD band of $4.62 and, after the 15-second limit state, Nasdaq declared a five-minute trading pause. The display-only period has started and imbalance messages are publishing.
Velloran Genomics (fictional), halt-cross imbalance messages to 10:18:30, ET (Illustrative)
Auction imbalance messages, not trades. Each row is a published indication before the auction; no shares traded at these prices.
| Time | Indicative price | Imbalance (shares) | Imbalance side |
|---|---|---|---|
| 10:15:00 | 4.70 | 60,000 | buy |
| 10:16:00 | 4.76 | 95,000 | buy |
| 10:17:00 | 4.80 | 140,000 | buy |
| 10:18:00 | 4.83 | 130,000 | buy |
| 10:18:30 | 4.84 | 120,000 | buy |
Imbalance messages during a LULD trading pause, not trades: indicative reopening price, imbalance shares and side. Upper band $4.62 triggered the pause at 10:14; upper auction collar about $4.85. Long 500 at $4.48; stop $4.38; limit sell $4.68 resting.
The plan, written before the halt. Long 500 shares at $4.48. Stop $4.38. Target: limit sell at $4.68 (2R), which stays on the book through the halt and is eligible for the reopening cross. Planned risk $0.10 per share, $50. Costs: $0.005 per share round trip (Illustrative). At 10:18:30 the stop cannot execute; the question is only where the first print lands.
Path AReopens above the target
The halt cross runs at $4.85. The resting $4.68 limit sell executes in the cross at the cross price.
Path BReopens far below the stop
The buy imbalance turns into a sell imbalance after a large holder sends sell orders into the cross. The halt cross runs at $4.10. The $4.38 stop triggers on that print and fills at $4.06.
Path CReopens near entry
The cross runs at $4.55. Price chops between $4.45 and $4.62 and the trader exits on a time stop at $4.52.
The review note is the same for all three: "Long into a limit-up pause; stop and target resting; 1R planned." Path A and Path B are about 8R apart, and both started from one book at 10:18:30. The rest of this lesson covers how the reopening auction works, how long halts can last, and how to size for a first print you cannot control.
How a LULD pause works
Under the LULD Plan (checked 2026-10-05), each NMS stock has price bands around a reference price, which is the average price of eligible trades over the preceding five minutes:
| Stock | Price | Band percentage |
|---|---|---|
| Tier 2 (most small caps) | above $3.00 | 10% |
| Tier 1 and Tier 2 | $0.75 to $3.00 | 20% |
| Tier 1 and Tier 2 | below $0.75 | the lesser of $0.15 or 75% |
| Tier 1 (S&P 500, Russell 1000, some ETPs) | above $3.00 | 5% |
Between 3:35 and 4:00 p.m. ET, the percentages double for all Tier 1 stocks and for Tier 2 stocks priced at $3.00 or less. Bands apply during regular trading hours. When the best offer sits at the lower band or the best bid at the upper band, the stock enters a limit state; if that lasts 15 seconds, a five-minute trading pause follows. No trades occur during the pause.
The reopening auction
For a Nasdaq-listed stock, the reopening runs through the Nasdaq Halt Cross (Rule 4120(c)(10) for LULD pauses, as published in SEC filings checked 2026-10-05):
- A five-minute display-only period. Orders can be entered; imbalance messages show an indicative price and imbalance.
- Auction collars. Under the rule, the reopening price falls inside collars built around the band that triggered the pause: 5% beyond it (or $0.15 for reference prices at or below $3.00) on that side, and the other band on the opposite side.
- Extensions. If the indicative price is outside the collar or market orders cannot all be matched, the halt extends by five minutes and the collar widens by another 5% in the imbalance direction. This repeats until trading resumes. There is no fixed maximum; a pause still unresolved at 3:50 p.m. goes into the closing process.
News and regulatory halts reopen through a similar halt cross with a five-minute display-only period. Since July 14, 2025, Nasdaq applies price collars to that cross as well (±10% at first, then wider with each extension). News-pending halts (code T1) have no fixed end; the resumption time is announced (code T3).
Market-wide circuit breakers are a different event: a 7% or 13% drop in the S&P 500 halts all stocks for 15 minutes if it happens before 3:25 p.m. ET, and a 20% drop halts trading for the rest of the day (Nasdaq circuit-breaker summary, checked 2026-10-05).
Limit vs. market orders into the cross
- A market order entered during the halt executes at the cross price, wherever it lands, if it is matched.
- A limit order executes only at its limit or better. A limit sell at $4.68 executes at $4.85 if the cross runs there; it does not execute if the cross runs at $4.10.
- A stop waits for the first trade, then becomes a market order. It does not take part in the auction as a price-protected order.
That is why Path B's stop filled below the reopening print: it triggered on the cross and then met the post-cross book. Marketable limit orders covers the ceiling trade-off.
Observe vs. infer
Go back to 10:18:30 in the Velloran example (fictional; all figures Illustrative).
| What the messages show (observed) | What a trader might infer | Why it is not established |
|---|---|---|
| Indicative price $4.84 with a 120,000-share buy imbalance at 10:18:30 | "It reopens higher" | The book can change until the cross, and collars can extend the halt |
| Indicative rose from $4.70 at 10:15:00 | "Momentum continues" | Earlier indicative prices are past snapshots of a book that is still changing |
| The halt was limit-up, not limit-down | "Halts up resume up" | The pause direction is a fact; the first print is not |
| A stop at $4.38 is in place | "Risk is $50" | The stop cannot act until after the cross |
Only the left column was usable at 10:18:30.
Odds box
If the Path B average is −4.5R instead of −3.5R, the expectancy falls to about −0.02R (computed from the assumed split, Illustrative). A few large gaps decide the sign, and their size is exactly the number a halt makes uncontrollable.
What shifts the odds
These are hypotheses to record, not findings, until that study is published:
- Halt type. Volatility pause vs. news pending; news-pending halts can last much longer.
- Direction of the pause. Limit-up vs. limit-down.
- Imbalance trend during the display period.
- Number of halts already today. A stock that paused once can pause again soon after reopening.
- Price tier. Sub-$3 stocks have 20% bands, so the move before a pause is larger.
- Time of day. Bands double between 3:35 and 4:00 p.m. ET for Tier 1 stocks and for Tier 2 stocks at or below $3.00.
Cost of being wrong
Using the Velloran position of 500 shares (Illustrative):
| Outcome | Exit | R after costs | Dollars after costs |
|---|---|---|---|
| Path A: cross above the target | $4.85 | +3.65R | +$182.50 |
| Path B: cross below the stop | $4.06 | −4.25R | −$212.50 |
| Path C: time stop | $4.52 | +0.35R | +$17.50 |
| Long halt, cross at $3.80 | $3.76 | −7.25R | −$362.50 |
Size so that the last row fits inside your daily loss limit. A halt is the case in which your stop is a plan for after the auction, not a limit on the loss.
How many trades before this means anything
Halts are rarer than ordinary entries, so samples grow slowly. With an Illustrative 20 held halts and 8 Path A outcomes (40%), the 95% Wilson interval runs from about 22% to 61% (computed from those Illustrative counts). The size of the Path B losses matters as much as their frequency. See How many trades before your numbers mean anything.
What this lesson does not claim
- It does not claim halts resume higher or lower. The odds box is Illustrative until the FennEdge data study of halt reopening prices is published.
- Rule descriptions summarize the LULD Plan and Nasdaq filings checked on 2026-10-05; NYSE and NYSE American reopen under their own rules.
- Velloran Genomics and its messages are fictional and Illustrative.
Go deeper
- FennEdge first.
- The Scanner (paid: Plus, Pro, Max; as of 2026-10-05) has halt and resume panels and triggers for Nasdaq-listed LULD halts only; it does not cover news halts. Halt price and volume shown there are last-known quotes, not necessarily the quote at the halt time.
- Articles: Trading halts (halt codes) and Limit up / limit down (LULD).
- Re-halts and stacked pauses. A stock can pause, reopen and pause again within minutes.
- Overnight trading. Status as of 2026-10-05: Nasdaq's overnight session was approved in April 2026, with a target start on or about 2026-12-06 that depends on SIP readiness and a further exchange filing; the consolidated data plans' extended-hours amendment was approved for the same date. The LULD Plan's overnight amendment (Amendment No. 27) uses static bands without automatic trading pauses overnight. Recheck after launch.
- Related: The opening cross, Shorting small caps, Parabolic moves, Stop-loss placement.
Exercises
Six exercises follow this lesson: three concept checks, one calculation (a gap-through loss after a limit-down pause), one replay of halt imbalance messages (classify observation vs. inference at 10:18:30, then Path B is revealed), and one scenario about orders during the display period. Exercises, answers and progress are available after signing in.
Primary sources
- LULD Plan: Plan to Address Extraordinary Market Volatility, Amendment 20.
- Nasdaq Rule 4120(c)(10): SEC Release No. 34-79876 and SEC Release No. 34-101620.
- Nasdaq halt cross price protections: SEC Release No. 34-102336 and Nasdaq Equity Trader Alert 2025-30.
- Nasdaq. Trading halt codes and market-wide circuit breakers.
- SEC. Investor bulletin on stop and stop-limit orders.
- SEC. Order approving Nasdaq's 23/5 trading session, Release No. 34-105199 (April 10, 2026).
- SEC. Order approving the UTP Plan extended-hours amendment, Release No. 34-105780 (June 26, 2026).
- SEC. Order approving LULD Plan Amendment No. 27 (overnight bands), Release No. 34-106042 (August 5, 2026).
Sources checked 2026-10-05. Velloran Genomics and all prices, messages, outcome splits and costs in this lesson are fictional and Illustrative. This lesson is education, not a recommendation to buy or sell any security. Past patterns do not indicate future results.