A price limit is a maximum distance a futures contract is allowed to move from a reference price before the exchange steps in. A circuit breaker is the mechanism that acts when a limit is reached: it either halts trading for a set time or locks the market so no trade can print beyond the band.

The point is to slow down panic, give the market a moment to find fair value, and prevent runaway cascades. These controls are set by CME Group and the exchanges (equity limits coordinate with NYSE Rule 7.12), not by Upcomers. They apply to every trader in the market at the same time.

Different product groups use different regimes. Equity index futures use fixed percentage circuit breakers. Energy and metals use rolling "dynamic" circuit breakers. Grains and livestock use fixed daily dollar limits. Here is what each one does.

This regime covers the index futures: ES, MES, NQ, MNQ, YM, MYM, RTY, M2K. During the regular US session the limits are measured as a decline from the prior day's S&P 500 closing price, in three levels.

The 15-minute halt is the coordinated regulatory halt (under NYSE Rule 7.12) that hits both the cash stock market and the equity index futures when the S&P 500 falls 7% or 13%. After a Level 1 or Level 2 halt, the market reopens and the limit steps out to the next tier (7% expands to 13%, then to 20%). A Level 1 or Level 2 decline reached at or after 3:25 p.m. ET does not halt the market. Only Level 3 still applies that late in the session.

Because these limits are index-percentage based, a micro contract moves on the same schedule as its parent. MES follows ES, MNQ follows NQ, and so on.

Outside the regular session, during electronic trading hours and the post-close window, equity index futures use a fixed 7% up and 7% down limit-up / limit-down band, measured against the daily futures fixing price (the volume-weighted average price of the lead contract over the last 30 seconds of the cash session).

The difference from the daytime rule matters. Overnight the market does not close at the band the way a Level 3 does in the day. It simply cannot trade past plus or minus 7%. It stays open, locked at the edge, until price comes back inside or the next session recalculates.

There is a second layer overnight. Alongside the 7% hard band, equity index futures also run a Dynamic Circuit Breaker of plus or minus 3.5%: a move of more than 3.5% within a rolling one-hour window pauses trading for about 2 minutes. So a violent overnight move can trigger a short 2-minute pause well before it ever reaches the 7% band. The 3.5% move is measured over the rolling window, not against a single fixed reference.

You may have seen a "2%" figure quoted for overnight limits. That is not a CME number. The overnight equity band is 7%, with the 3.5% pause inside it. The 2% usually refers to a buffer some prop firms impose on their own traders: do not trade within 2% of a limit, which for equities means they suspend you at a 5% net move. That is a firm policy, not an exchange limit. Upcomers does not currently publish such a near-limit trading rule.

Energy (CL, MCL, QM, NG, QG, HO, RB) and metals (GC, MGC, SI, SIL, HG, MHG, PL, PA) do not use a single fixed daily percentage. They use Dynamic Circuit Breakers.

A dynamic circuit breaker tracks a rolling 60-minute window of highs and lows and sets a band around it that moves with the market all session. When price hits the band, the contract goes into a short 2-minute pause (a pre-open state where orders can be entered, changed, or cancelled but nothing matches). Trading then resumes with a recalculated band.

Energy and metals share the same core trigger: a move of roughly 10% of the prior settlement inside the rolling one-hour window is the kind of event that sends the contract into the 2-minute pause. That covers crude and natural gas on the energy side and gold, silver, and copper on the metals side. In the last few minutes before daily settlement the pause shrinks from 2 minutes to about 5 seconds.

The exact band width is derived off each product's own prior settlement, so the precise number can differ slightly per contract.

The rest of the launch universe follows its own regimes. The principle never changes: when a market moves too far too fast, the exchange pauses it or bands it. Only the numbers differ.

Grains and livestock (ZC, ZS, ZW, ZL, ZM, HE, LE, GF) mostly use fixed daily price limits, a set dollar band above and below the prior settlement, published per product and often expanded after a limit day. These are not the rolling dynamic breakers that energy and metals use.

FX (6E and the other currency futures), interest-rate futures (ZB, ZN, ZF, ZT, UB), and CME crypto (BTC, MBT, ETH, MET) each have their own exchange-set limit mechanisms, again a pause or a band when a move is violent enough. The exact parameters vary by product.

In practice a limit event shows up as one of three states. Knowing which one you are in tells you what you can and cannot do.

1. Halt or pause. No orders match. You cannot get in or out. Your open position is frozen at whatever equity it had the moment the halt hit (15 minutes for an equity Level 1 or Level 2, the rest of the day for Level 3, about 2 minutes for an energy or metals dynamic circuit breaker). You can queue and cancel orders, but they sit unfilled until the market reopens.

2. Limit or locked state. The market is technically open but can only trade inside the band. If price is pinned at limit-down, there may be no bids above the limit, so a sell order may simply not fill even though nothing is "halted". Stops can go unfilled or fill far away when the market unlocks.

3. Order rejection. Any order priced beyond the prevailing limit is rejected by the matching engine. If you try to sell below the down-limit, the order is refused. This is expected behavior, not a platform bug.

On a funded account the risk is not the limit itself, it is being stuck on the wrong side of one while a drawdown rule keeps counting.

Drawdown during a halt. Upcomers funded accounts run a real-time trailing drawdown (the Dynamic Risk Shield™) plus a daily drawdown that resets at 5:00 p.m. ET. The daily drawdown is 2% on Thunderbolt Classic and Vanguard, 3% on Thunderbolt Legacy. On a $100,000 account that is $2,000 or $3,000.

The Dynamic Risk Shield™ trails your equity higher in real time as you profit, then locks permanently at your initial balance once the account grows by the trailing percentage (4% on Thunderbolt Classic and Legacy, 3% on Vanguard). Once locked, it stays static, the same lock model as the CFD Dynamic Risk Shield™.

Here is the trap. If a circuit breaker freezes you in a losing position, your equity may already be at or below a threshold and you cannot close to defend it until the market reopens. When a drawdown limit is breached, all open positions close at market automatically at the system level. Because the drawdown is tracked in real time on every product, a gap on reopen can breach you before you get a chance to act.

Max Trade Loss (1.5%). A limit-down move can blow through a stop. Because a stop becomes a market order once triggered, and a locked-limit book may have no counterparty, the eventual fill on reopen can be far worse than your stop price and can push a single trade past the 1.5% Max Trade Loss (on a $100,000 account, that is $1,500). Max Trade Loss is a hard rule. A single trade that exceeds it triggers an automatic breach and the account is terminated, even if your account is otherwise in profit. Positions on the same instrument in the same direction count together as one trade, so you cannot split an oversized position to stay under the limit.

Stops are not guarantees in a locked market. Do not assume a stop protects you during a limit event. If there is nobody to trade with inside the band, the protection you thought you had may not execute until price clears the limit.

Overnight and weekend holds. Thunderbolt Legacy allows overnight and weekend positions. The 7% overnight band means an adverse gap can be capped, but you are stuck at the limit with no exit until it clears. Combined with Legacy's real-time trailing drawdown and its 3% daily drawdown, that is a real exposure to plan for before you hold through a session break.

Price limits and circuit breakers are a normal part of trading CME futures. They are not something to fear, but they are something to respect. Size your positions and place your stops with the understanding that in a fast, one-directional market you may not be able to exit exactly when or where you want. Trading with room to spare from your drawdown thresholds is the simplest protection against a limit event catching you off guard.

If you ever see a halted instrument or a rejected order during a sharp move, this is why. Wait for the market to reopen and manage the position from there.

Is a halt a platform error or an Upcomers rule?

Neither. Price limits and circuit breakers are set by CME Group and the exchanges. Every trader in the market hits them at the same instant.

Can a circuit breaker breach my account?

Not by itself, but it can trap you. If a halt or a locked-limit market freezes you in a losing position, your drawdown rules keep applying and you cannot close to defend your equity until the market reopens.

My order was rejected during a fast move. Why?

Any order priced beyond the prevailing limit is refused by the matching engine. That is expected, not a bug. Wait for the market to reopen and re-enter inside the band.

Does my stop still protect me?

A stop becomes a market order when it triggers. In a locked-limit market there may be no counterparty inside the band, so the fill on reopen can land far from your stop price. Treat a stop as a plan, not a guarantee, during a limit event.