← Back to Blog · 2026-09-16 · 8 min read · Trading Education

You've done your analysis. Thermal coal has been ripping higher for weeks, momentum is unmistakable, and you go long three lots because "it's just coal, how fast can it move?" Two sessions later, the exchange hikes margins, the price limit widens, your position is down more than your planned monthly risk, and you can't even exit cleanly because the contract opened limit-down. If this scenario feels painfully specific, it's because a version of it happened to thousands of traders during the 2021 thermal coal rally — one of the most violent moves Chinese commodity futures have produced in recent memory.

Here's the uncomfortable truth: most retail traders trading China futures don't blow up because their analysis was wrong. They blow up because their position size turned a normal losing trade into an account-ending event. In high-volatility Chinese commodity futures, position sizing isn't a back-office detail. It's the whole game.

This article gives you concrete, workable sizing rules — built around real contract specifications — that you can apply to rebar, iron ore, thermal coal, methanol, copper, and beyond.

Why Chinese Commodity Futures Punish Lazy Position Sizing

Chinese commodity futures have a personality that catches Western-trained traders off guard. Three structural features drive it:

• Steep contract multipliers. A single lot of iron ore on the Dalian Commodity Exchange (DCE) represents 100 metric tons. Rebar on the Shanghai Futures Exchange (SHFE) is 10 tons per lot. One tick of rebar is 1 yuan per ton — meaning 10 yuan per lot — but a 50-yuan intraday swing is routine, which is 500 yuan per lot before you've done anything clever.
• Aggressive leverage. Exchange minimum margins are often in the 5%–12% range depending on the product and market conditions, and brokers add a buffer on top. That means headline notional exposure per lot can be 8–20x your margin posted. Leverage doesn't increase your edge — it only amplifies the size decision you've already made.
• Price limits and gap behavior. Chinese exchanges apply daily price limits (commonly around 4%–10% depending on the product, and these get widened during volatile periods). When a limit move happens, liquidity can vanish. You can be right on direction and still take a fill far worse than your stop, because your stop simply didn't exist at that price.

Add night sessions — where Chinese contracts trade while US and European markets are moving — and you have a market where overnight gaps are a normal Tuesday, not a black swan. Your sizing has to assume the stop-loss price is a suggestion, not a guarantee.

Step One: Know Exactly What One Lot Costs You to Move

You cannot size a position on a contract you can't price in cash terms. Before anything else, internalize the tick value of what you're trading. Here are widely published specs for some of the most liquid Chinese commodity contracts:

(Always verify current specs with the exchange and your broker — exchanges do adjust tick sizes, margins, and limits, sometimes with little warning during volatile periods.)

Now do the math that actually matters: how much cash moves per lot for a typical daily range? Take rebar trading around 3,500–4,000 yuan per ton. A daily range of 1.5% is roughly 55–60 yuan per ton, or around 550–600 yuan per lot. Iron ore around 800 yuan per ton with a 2% range is roughly 16 yuan per ton — about 1,600 yuan per lot. That's the terrain you're standing on. If your account is $5,000 and you're long five lots of iron ore, a single ordinary day can move your equity by a mid-three-figure dollar amount. Sizing decisions made without this arithmetic are just vibes.

The Core Rule: Fixed Fractional Risk, Not Fixed Lot Count

The single most important habit in Chinese commodity futures is sizing by risk, not by lots. The formula is boring and non-negotiable:

Lots = (Account × Risk %) ÷ (Stop Distance in ticks × Tick Value)

Worked example. You trade a $10,000 account and risk 1% per trade — $100. You're long rebar with a stop 40 yuan per ton below entry (a reasonable structure-based stop, not a hope-based one). Your risk per lot is 40 × 10 = 400 yuan, roughly $55–60 at typical exchange rates. That gives you:

$100 ÷ ~$57 ≈ 1 lot. Not three. Not five. One.

Notice what this does psychologically: your maximum loss on a normal stop-out is a rounding error in your month, not a crisis. That's what lets you hold your plan when the market gets loud — which in Chinese commodities it will.

Set a hard risk ceiling per trade

For Chinese commodity futures specifically, keep per-trade risk at 0.5%–1% of account equity. If you're newer to these markets or trading through a period of elevated volatility (post-holiday sessions, policy-driven moves, margin hikes), drop to 0.5%. The 2% rule that works fine in liquid Western index futures is too generous here, because gap risk means your realized loss can exceed your planned loss. Size for the gap, not for the stop.

Volatility-Adjusted Sizing: Use ATR, Not Feelings

A fixed 40-yuan stop on rebar means very different things in a quiet February versus a chaotic October. The fix is to let measured volatility dictate your size. The cleanest tool is a simple 14-period Average True Range (ATR) on your trading timeframe.

The logic: as volatility rises, your stop gets wider, so your size must shrink. Same dollar risk, same trade thesis, smaller position. This is the exact discipline that keeps traders alive through events like the 2021 thermal coal surge, where policy interventions and exchange rule changes produced consecutive limit moves that no tight stop could have protected.

A practical ATR sizing workflow

• Calculate ATR(14) on your trading timeframe (daily is most common for these markets).
• Set your stop at a minimum of 1–1.5x ATR from entry. Anything tighter gets noise-stopped constantly.
• Compute lots with the fixed fractional formula using that ATR-based stop distance.
• Recalculate weekly. When ATR doubles, your size halves. No exceptions, no "but the setup is so good."

One more volatility rule specific to China: check the exchange's current margin and price-limit parameters before every session. During high-volatility stretches, exchanges have repeatedly raised margins and widened limits on hot contracts. A position that fit your risk budget at 8% margin may not fit at 15%. If a margin hike pushes your position beyond your planned exposure, cut size the same day — don't wait for the market to do it for you.

Respect the Gap: Sizing for Limit-Move Risk

This is the section most sizing articles skip, and it's the one that matters most in Chinese commodity futures. Your stop-loss is an instruction to exit at approximately a price. In a limit-move or a violent overnight session, "approximately" can mean a lot.

Three rules to bake this in:

• Stress-test your position against a full limit move. Before entering, ask: if this contract opens tomorrow at its daily limit against me and I can't exit until later, what does that cost me? If the answer is more than 3–4% of your account, the position is too big — regardless of how tight your stop is.
• Size down around event risk. Chinese commodity markets are unusually sensitive to policy announcements — production curbs, import/export adjustments, environmental mandates. Ahead of major scheduled policy windows or after a contract has already posted several consecutive limit moves, halve your normal size or stand aside. The 2020 oil crash showed global markets how fast a gap can destroy a leveraged position; Chinese contracts have their own versions of that dynamic.
• Cap total portfolio heat. Limit open risk across all Chinese commodity positions to roughly 3% of account equity. These markets are correlated — rebar, iron ore, and coke all lean on the same steel-and-construction complex. Five "independent" positions can behave like one giant bet on Chinese infrastructure demand.

Practical Application: A Full Sizing Example with Iron Ore

Let's put the whole system together. Account: $10,000. Risk per trade: 1% = $100. Setup: short iron ore after a failed rally, DCE contract, 100 tons per lot, tick value 50 yuan per 0.5-yuan move.

• Daily ATR is running around 2.2% of a roughly 850-yuan/ton price — call it about 18–19 yuan per ton.
• You place your stop 1.5x ATR above entry: roughly 28 yuan per ton of risk per lot, or about 2,800 yuan ≈ $390 per lot.
• Lots = $100 ÷ $390 = 0.26 → you cannot trade this setup at 1% risk. Minimum viable size is zero lots.

That last line is a feature, not a bug. On a smaller account, some Chinese commodity contracts simply don't fit, and the correct move is to trade a smaller-multiplier contract instead, or skip the trade. Forcing size where the math says no is how accounts die. If the setup only justifies a quarter lot, either find a contract whose multiplier fits your account or pass. There is always another session.

Contrast: same account, same 1% risk, but you trade methanol (10 tons/lot) with a 45-yuan/ton stop. Risk per lot ≈ 450 yuan ≈ $63. Now the formula gives you one lot — a legitimate, correctly-sized trade.

Your pre-trade checklist

• Tick value and current margin requirement confirmed with the exchange/broker today, not last month.
• Stop distance ≥ 1x ATR, structure-justified.
• Lots computed from fixed fractional risk — never from "how much margin I have free."
• Limit-move stress test passes: full adverse limit move ≤ 3–4% of account.
• Total open heat across correlated Chinese commodity positions ≤ 3%.

Sizing Is the Edge You Control

Nobody — including you — knows whether the next rebar breakout will follow through. But you know exactly what one lot of iron ore costs to move, what your stop distance is, and how many lots fit inside 1% of your account. That certainty is your actual edge in Chinese commodity futures. The traders who last in these markets aren't the ones with the best macro calls; they're the ones whose position size survives being wrong five times in a row and still leaves them in the game.

Build the rules, write them down, and then test them against real market data — not in your head, where every plan works. If you want to put a complete sizing system through its paces on real Chinese futures data, XS Select runs a China futures evaluation where you can trade a simulated evaluation account on live market conditions from $29. It's the cheapest tuition you'll ever pay on the difference between a sizing rule and a sizing habit.