GC Margin: Day vs Overnight Explained
Gold futures (GC) margin is simple on paper and brutal in practice. You’ve got exchange margin, broker day-trade margin, and overnight margin. If you don’t know the difference, you’re handing your account to volatility with a bow on it.
The GC Margin Stack: Exchange vs Broker
There are two layers of margin you need to understand for GC:
- Exchange margin – what CME requires from your broker for each contract.
- Broker margin – what your broker chooses to require from you.
CME sets initial and maintenance margin per GC contract. Brokers then decide:
- how much to require intraday (day-trade margin)
- whether they even offer reduced intraday margin
- what you must hold to stay in an overnight position
So GC margin isn’t one number. It’s a stack of rules.
Exchange Margin Basics for GC
CME publishes initial and maintenance margin for GC and updates it when volatility spikes or calms down. The maintenance margin is the minimum you must hold to keep the position open. Initial margin is slightly higher and is what you need to open the position.
| Type | What It Means |
|---|---|
| Initial Margin | Capital required to open 1 GC contract |
| Maintenance Margin | Minimum equity to keep that contract open |
Actual dollar values move over time, but they’re always sized for the reality that one GC contract controls 100 oz of gold. If you don’t know what that means in tick terms, read GC tick size and tick value.
Day-Trade Margin on GC: Broker Leverage
Day-trade margin is a broker invention, not a CME concept. Brokers slash the required capital during set intraday hours to attract active traders. You might see something like:
- GC intraday margin: a fraction of exchange initial margin
- GC overnight margin: at or near full exchange initial margin
That discount is leverage, not a favor. GC can move dozens of ticks fast. A “cheap” intraday margin requirement just means the broker lets you put on more contracts than you realistically should.
Overnight Margin on GC: Where People Blow Up
Overnight margin is where reality shows up. Once the broker’s “day session” ends, they want you at or above a much higher equity requirement to keep the contract.
Three ways traders get wrecked:
- They forget when day margins end.
- They’re overleveraged intraday and can’t hold overnight.
- The broker auto-flattens them into a bad fill when the bell hits.
If you can’t comfortably meet overnight margin on GC, you shouldn’t be swinging that contract. Period.
Example: How GC Margin and Volatility Interact
Forget the exact CME numbers and look at the mechanics. GC tick value is fixed: $10 per tick per contract. GC can easily move 50–100 ticks around major economic reports.
- 50 ticks × $10 = $500 per contract
- 100 ticks × $10 = $1,000 per contract
If your broker lets you open a GC with a low day-trade margin and you size up to 3–5 contracts “because you can,” a normal GC news move can swing your account thousands in minutes. That’s not the broker’s fault. That’s you not understanding the product. If you don’t understand GC’s behavior during key windows, read the timing article.
GC Margin and Account Size: What Actually Matters
Margin should never be your sizing target. It’s the minimum the system demands, not the smart risk number. For GC:
- one contract controls 100 ounces
- every 1.0 move in price = 10 points = 100 ticks = $1,000 per contract
Ask yourself a basic question before you enter:
- “If GC moves 2–3 points against me, can my account survive that?”
If the answer is no, you either:
- trade MGC instead
- cut your contract count
- or don’t trade GC at all until your account is bigger
That’s the same position sizing logic I lay out for ES in this position sizing article.
Why GC Overnight Risk Is a Different Game
Holding GC overnight brings in:
- gap risk from macro headlines
- liquidity changes when sessions open/close
- spread widening during roll, holidays, and thin hours
Your broker’s overnight margin requirement is them pricing in that risk. It’s not arbitrary. If you want to swing GC, size for the overnight margin, not the cute intraday discount.
Final Takeaway: Margin Is a Floor, Not a Goal
GC margin requirements exist to keep the system from blowing up, not to protect you from your own leverage addiction. Exchange margin is the hard requirement. Broker day-trade margin is a marketing lever. Overnight margin is where risk gets real. If you understand GC tick value, contract size, and margin structure, you’ll stop sizing off what the broker “allows” and start sizing off what your account can actually handle.