Margin is the deposit your broker holds while you hold a futures position — and micro futures margins are the lowest in the index-futures world. But "day margin" and "overnight margin" are two very different numbers. Here's how they work.
Day Margin vs. Overnight Margin
- Day (intraday) margin: applies while you're in a trade during the day session. Brokers offer big discounts here — often $50–$100 per micro contract.
- Overnight (initial) margin: applies if you hold past the session close. This is set closer to the exchange minimum and is far higher.
- Maintenance margin: the minimum equity you must maintain while holding; if your account falls below it, you get a margin call.
The catch: if you enter with $50 day margin but hold into the overnight session, your broker now requires the full overnight margin. Not having it can force a liquidation at a bad price.
Typical Margin by Contract (Approximate, 2026)
| Contract | Day Margin | Overnight Margin (approx.) |
|---|---|---|
| MES (S&P 500) | $50–$100 | $1,000–$1,500 |
| MNQ (Nasdaq) | $50–$100 | $1,500–$2,000 |
| MYM (Dow) | $50–$100 | $600–$900 |
| M2K (Russell) | $50–$100 | $500–$800 |
These are representative ranges. Margins are set by each broker and by the exchange (CME), and they change — especially around volatile events.
How Brokers Set Micro Margins
Two layers are involved:
- Exchange (CME) minimums — the floor that brokers can't go below for overnight positions.
- Broker add-ons — each broker adds its own risk buffer, and discount brokers compete on razor-thin intraday margins.
That competition is why you'll see "$50 micro margins" advertised — the brokers are using low intraday margins to attract day traders, betting that most positions close before the overnight requirement kicks in.
How to Check Your Actual Margin
Never trust a review for the exact number — check your broker's live margin page:
- Go to your broker's margin requirements page (every serious futures broker has one).
- Find the symbol (MES, MNQ, MYM, M2K).
- Read both the day and overnight/initial columns.
Most brokers also show current margin inside the trading platform next to the order ticket.
Why Margin Matters for Prop Firm Traders
In a futures prop firm evaluation, the firm often sets its own simplified margin rules and drawdown limits on top of the exchange's. Understanding real micro margins helps you reason about position sizing, but the number that actually governs your funded account is the firm's drawdown rule — not the broker's margin. Keep the two separate.
A Worked Example: The Day-to-Overnight Trap
You open one MNQ at 4:00 PM with $50 day margin. The trade goes slightly against you, so you decide to hold it "just until tomorrow." At the session close, your broker's overnight margin requirement kicks in — now you need roughly $1,800 for that same one contract.
If your account only has a few hundred dollars in it, the broker can force-liquidate your position at the worst moment. This is the single most common way micro futures beginners get surprised. Know both margins before you hold anything.
Margin Mistakes That Trigger Liquidation
- Holding day trades overnight — the margin requirement jumps 10-30x.
- Not knowing maintenance margin — equity can fall below the requirement even while the position is "still open."
- Trusting a review's numbers — margins change, especially around volatility. Check your broker's live page.
- Adding contracts without re-checking margin — each extra contract multiplies the requirement.
FAQ: Micro Futures Margin
Why is day margin so much lower? Brokers discount intraday margin to attract day traders, betting most positions close before the overnight requirement applies.
Do margin requirements change? Yes — exchanges and brokers adjust them, often higher during volatile periods.
Does a prop firm use the same margin? Usually not — prop firms set their own simplified rules and drawdown limits on top of the exchange.
Quick Reference: Margin Cheat Sheet
| Term | What It Means |
|---|---|
| Day margin | Deposit to hold a position during the day session (lowest, ~$50–$100 for micros) |
| Overnight / initial margin | Deposit to hold past the close (much higher) |
| Maintenance margin | Minimum equity while holding; below it triggers a margin call |
If you only remember one thing: the margin you entered with at 9:00 AM is not the margin you need at 5:00 PM.
Bottom Line
Micro futures margins are cheap intraday ($50–$100) but jump hard overnight ($500–$2,000+). Know both numbers, close or fund for overnight if you hold, and always check your broker's live page rather than relying on a summary like this one.