SI Margin Requirements: Day vs Overnight
Most traders blow up in Silver futures (SI) long before they understand how margin actually works. SI isn’t a small contract. It’s 5,000 ounces × whatever the price is. When brokers give you low day margin, they’re basically handing you a loaded weapon. This article breaks down day vs overnight margin, how CME sets requirements, and how the math translates into real risk.
What Margin Actually Is in SI Futures
Margin in SI isn’t a “fee” or a “cost.” It’s a performance bond—money the exchange forces you to post so you can handle unrealized losses without defaulting. Your broker can offer reduced intraday margin, but they can’t change CME’s real overnight numbers.
| Margin Type | Who Sets It? | What It Controls? |
|---|---|---|
| Day (Intraday) Margin | Your broker | Your buying power only during open hours |
| Initial / Overnight Margin | CME | Your minimum required capital to hold past close |
| Maintenance Margin | CME | Minimum amount before a margin call |
If you don’t know which one applies when, SI will bury you.
Day Trading Margin (Intraday) — The Bait
Day margin is the broker’s “trust me bro” margin. It’s artificially low so retail can trade contracts they shouldn’t be touching.
For SI, brokers often offer:
- $800–$1,500 day margin
- Some go as low as $500 during regular hours
Sounds great until you realize:
- SI’s typical 1-minute ATR during active periods is 4–10 ticks ($100–$250)
- A 20–40 tick move happens constantly ($500–$1,000)
- Economic releases can drive 120+ ticks ($3,000)
Day margin is not “safe.” It’s the exchange letting you borrow volatility.
Overnight Margin — The Part You Can’t Escape
Overnight margin is the real requirement. You hold past the session close? You must meet CME’s numbers, not your broker’s round-number fantasy.
Typical SI numbers (approximate because CME changes with volatility):
- Initial Margin: ~$9,000
- Maintenance: ~$8,000
If your account can’t cover this, your broker flattens your position automatically. No debate.
Why CME Margin Is So Much Higher
CME sets overnight margin based on realized volatility. It’s math. If SI’s volatility spikes, margin spikes too. CME isn’t protecting you—they’re protecting the clearing house. You’re just along for the ride.
Here’s the math that justifies the high margin:
- SI often moves 0.75–1.20 dollars in a normal day
- 1 dollar = 200 ticks
- 200 ticks × $25 per tick = $5,000
That’s the baseline daily move. Big days double it. Margin must be able to survive overnight moves, gaps, news, and no-liquidity moments.
Why Day Margin Gets Traders Killed
Take a trader with $2,000 in their account and $1,000 day margin. They enter one SI contract. SI moves 50 ticks (common during any U.S. data window).
50 ticks × $25 = $1,250 unrealized loss. Trader now has $750 margin left and probably a margin call. Does SI care? Of course not—it’s a 5,000-ounce contract with institutional flows.
The “Margin Cliff” — Where Things Go Really Wrong
Every futures trader eventually meets the margin cliff: when intraday margin magically becomes irrelevant because you accidentally held into the close—or your broker decides volatility is too high and raises margin mid-session.
When that happens:
- Your required margin jumps from $1,000 → $9,000 instantly.
- Your account equity doesn’t change.
- Your broker liquidates you without mercy.
This is why pros size for overnight margin even when day-trading.
Volatility-Based Margin Adjustments
CME adjusts SI margins when realized volatility spikes. These situations trigger margin hikes:
- Huge CPI or NFP moves
- Dollar volatility surges
- Silver supply disruptions
- Massive COMEX inventory changes
- Risk-off shocks or geopolitical news
Margin spikes make SI harder to hold long-term—but safer to trade intraday because overnight blowout risk drops.
Risk Management Reality Check
If you want to survive in SI trading:
- Trade with size small enough to meet overnight margin, even if day trading.
- Never hold SI into unknown high-impact news unless you size correctly.
- Don’t use day margin as “permission” to be reckless.
- Recognize that margin = volatility exposure, not a guideline.
You can’t cheat leverage math. SI punishes people who try.
Final Takeaway
Day margin in SI is bait. Overnight margin is the reality. If you structure risk based on the fake number instead of the real one, SI will crush you when volatility spikes or when the close rolls around. Treat overnight margin as the minimum capital required to play the game, no matter when you enter, and SI becomes survivable instead of a liquidation generator.