← Back to Blog · 2026-09-26 · 8 min read · Strategy Case Study

Every trader has one market they watched happen without them. For a lot of people trading Chinese commodity futures, 2021 was that year. Steel, coal, chemicals — entire sectors went vertical while most retail traders sat on the sidelines, either too intimidated by the Shanghai Futures Exchange or too busy losing money fighting the trend with fading strategies.

Here's the uncomfortable question this article answers: if you had applied one of the dumbest, most battle-tested approaches in trading — a simple trend-following breakout — to rebar futures in 2021, what would it actually have returned? Not a fantasy number. A rough, honest reconstruction using real contract specs and rules you could have written on a napkin.

Let's dig in.

What Actually Happened in 2021 (The 60-Second Version)

2021 was a perfect storm for Chinese industrial commodities, and the drivers were public knowledge at the time:

• Post-COVID demand recovery. China's economy rebounded hard through 2020 and into 2021, and infrastructure and construction activity pulled steel demand with it.
• Supply-side squeeze. The government committed to cutting crude steel output year-over-year, and later in the year the "dual control" energy consumption policy forced production curbs across steel mills, coking, and energy-intensive industries. Less supply, same demand — you know how that movie ends.
• The thermal coal explosion. Coal futures on the Zhengzhou exchange became the poster child of the rally, with prices multiplying several-fold before regulators stepped in around October and prices collapsed almost as fast as they rose.

Rebar rode the same wave. Steel reinforcement bar futures on the Shanghai Futures Exchange rallied strongly through the first half of the year, hit what was then record territory around May, took a sharp hit when the government publicly warned against speculation and commodity hoarding, then staged a second leg higher in late summer as production cuts bit harder. The final top came in the autumn, followed by a steep unwind as Beijing intervened across the coal and steel complex.

That shape matters: two big up-legs, a violent mid-year correction, and a brutal final breakdown. A trend system had to survive all four phases to keep the money. Keep that in mind as we go.

Know Your Instrument: The Rebar Contract

Before any backtest talk, here's what you're actually trading. Rebar (ticker RB) on the Shanghai Futures Exchange is one of the most liquid contracts in the world by volume:

• Exchange: Shanghai Futures Exchange (SHFE)
• Contract size: 10 metric tons per lot
• Quote: yuan per ton
• Minimum tick: 1 yuan/ton, so 10 yuan per tick per lot
• Sessions: day session plus a night session — genuinely useful for overseas traders, since part of the night session overlaps with European hours

Do the math on exposure: at a price of roughly 5,000 yuan/ton — which is roughly where rebar spent much of 2021 — one lot controls about 50,000 yuan of notional. At the time, that was somewhere around $7,500-8,000 USD depending on the exchange rate. With exchange minimum margins often in the 10-15% range for such contracts (and brokers adding a cushion on top), one lot required roughly $800-1,500 in margin. This is a retail-accessible instrument, not an institutional toy.

One point of leverage math worth internalizing: a 500 yuan/ton move — which rebar could do in a week during 2021 — equals 5,000 yuan per lot, or roughly 10% of notional. Trend following on Chinese commodity futures is not a slow game.

The Rules: Deliberately Dumb

For this case study I'm using a classic Donchian-style breakout, the same family of logic behind the famous Turtle rules. Nothing optimized, nothing fancy:

• Entry: Go long when price closes above the highest close of the previous 20 trading days.
• Exit: Exit when price closes below the lowest close of the previous 10 trading days.
• Risk per trade: Size the position so the initial stop (placed at the 10-day low at entry) risks no more than 1% of the account.
• No re-entry limit: Whipsawed out? Fine. The next breakout gets taken anyway.
• No fundamental overlay. No "but the government might intervene" filters. That's the whole point of the exercise.

Why so simple? Because the failure mode of most retail traders in a raging bull market isn't bad entries — it's exiting winners early and re-entering emotionally. A mechanical 20/10 structure removes both decisions. You will get chopped up in ranges. That's the tuition. The trend legs pay for it.

Walking Through 2021 With These Rules

I'm not going to pretend this is a tick-precise backtest — think of this as a careful reconstruction, with numbers kept honest and approximate. Here's how the year would have unfolded:

Leg one: the spring rally

Rebar trended steadily higher through the first months of 2021. A 20-day breakout triggers somewhere in the first quarter, and the position just... stays on. Each new 10-day low keeps ratcheting higher without being hit. By the time rebar pushed into record territory around May — well above the prior historical range — the system was sitting on a multiple-R winner. On a 1%-risk-per-trade framework, a move of that magnitude and duration is worth roughly 5-8R depending on exactly where the entry and trail landed. Call it the best trade of the year, and it required zero decisions after entry.

The May shakeout

Mid-year, Chinese authorities publicly warned speculators and moved to curb commodity hoarding. Rebar dropped hard and fast — the kind of decline that takes back a third or more of a rally in weeks. The 10-day trailing exit would have caught a decent chunk of the top, giving back maybe 1.5-2R from the peak but locking in the bulk of the gain. This is the part trend traders have to make peace with: you never exit at the top. You exit 10 days after the top, slightly bruised, still up big.

Leg two: the autumn run

After a summer of consolidation, production cuts intensified and rebar staged a second rally into the early autumn. The system re-enters on a fresh 20-day breakout — no hesitation, no "it already ran too far." This leg was shorter and choppier than the first, worth maybe 2-3R before the exit triggered.

The October collapse

When regulators intervened aggressively in the coal market around October, the entire ferrous complex unwound violently, and rebar fell with it. Here's the beautiful part of the mechanical exit: the 10-day close-below rule got you out early in the breakdown. And if you were running the system symmetrically — taking shorts on 20-day downside breakouts — the final leg of 2021 was itself a short-side trend trade. The same rules that made money on the way up handed you the short on the way down.

The honest scoreboard

Add it up, subtract the inevitable whipsaw losses in the sideways stretches (there were a handful of small 1R stop-outs), and a rough estimate lands in the neighborhood of +8R to +12R for the year. At 1% risk per trade, that's roughly +8% to +12% on the account with strict sizing. With more aggressive — but still defensible — risk of 2-3% per trade, it's a 20-35% year.

Is that spectacular? No. Is it remarkable given the system has four rules and zero opinions? Yes. And note what the system didn't do: it didn't catch the exact top, didn't front-run the policy intervention, didn't avoid the whipsaws. It just refused to argue with the trend.

Why Most Traders Still Lost Money in That Market

This is the section that actually matters, because 2021 was a market where simply being long steel for most of the year printed money — and plenty of retail traders still lost. The usual suspects:

• Fading every new high. "It's up too much, it has to pull back." It did pull back — after doubling. Shorting a parabolic trend driven by genuine supply destruction is how accounts die.
• Trading the news instead of the tape. Every government statement about curbing speculation was read as "the top is in." Sometimes it was. Often it wasn't. The 10-day exit knew without knowing.
• Position sizing from ego. With 10x-plus effective leverage available, a trader risking 10% per trade on rebar didn't survive the May shakeout to see the autumn leg.
• No exit plan. Traders who rode the spring rally into October gave back everything and then some. An entry without a mechanical exit is a hope, not a trade.

The 2021 rebar run is a near-perfect natural experiment: same market, same information available to everyone, wildly different outcomes — sorted almost entirely by process.

How to Actually Apply This

If you want to trade rebar, iron ore, or the broader Chinese commodity futures complex with this kind of approach, a few practical notes:

• Start with the exit, not the entry. Decide your trailing rule before you ever look for a breakout. The exit is where trend systems live or die.
• Respect the contract specs. Rebar's 10-ton multiplier and 1-yuan tick make risk math refreshingly clean. Iron ore on the Dalian exchange runs 100 tons per lot — different beast, do the notional math before sizing.
• Use the night session. Trends in Chinese commodities often move while New York sleeps. If you're trading these markets from overseas, the night session is where a lot of the action is.
• Expect the chop. A 20/10 system loses small, frequently, in ranges. In 2021 the trend legs paid for all of it. In a sideways year, the same system bleeds. Know which regime you're in — or accept paying the tuition automatically.
• Backtest on real data, not memory. Your brain remembers the parabola and forgets the six weeks of chop before every breakout. Reconstructing 2021 from memory is exactly how people convince themselves a system is better than it is.

That last point is the whole game, honestly. A rule set that looks obvious in hindsight was deeply uncomfortable in real time — through the May warning headlines, through every "this must be the top" moment. The only way to know whether you can actually execute it is to run it against real historical data, then run yourself against it in live conditions.

Before You Trade the Next 2021

China's commodity markets will produce another 2021 eventually — supply policies, demand cycles, and speculative flows guarantee it. The traders who profit from it won't be the ones who predict it. They'll be the ones whose rules made riding it automatic.

If this kind of case study is how you like to learn, one practical suggestion: build your version of the system, then test it under real conditions before committing capital. That's exactly what we built XS Select for — it's a China futures evaluation platform where you can run your strategy against real Chinese market data and trade a funded evaluation, with challenges starting from $29. No promises about what you'll make — 2021 was 2021, and the next trend won't ask your opinion. But the traders who show up with a tested process are the ones still standing when it arrives.

Trade the trend. Size it small. Let the exit do the thinking.