← Back to Blog · 2026-10-21 · 7 min read · Market Preview

You stare at your screen. The Shanghai Futures Exchange (SHFE) rebar contract is trending up, but the spot price in Tangshan hasn't budged. You feel the itch to jump in on the long side, driven by the momentum of the futures chart. Then, a flash of red hits your portfolio. You weren't trading the trend; you were trading the basis, and you got crushed by a sudden inventory build that no one mentioned in the morning news.

This is the silent killer for many global traders attempting to enter the Chinese commodity markets. Unlike US or European markets where inventory data is often lagging or aggregated differently, China offers near-real-time visibility into warehouse stocks through mandated exchange reports. For the savvy trader, these reports are not just data points—they are the primary engine for basis trading.

Today, we are stripping away the noise. We aren't here to talk about technical indicators that lag by hours. We are here to talk about the fundamental mechanics of China futures: specifically, how to interpret warehouse stock reports to identify high-probability basis trades in contracts like rebar, iron ore, and copper. If you want to survive the volatility of Chinese commodity futures, you need to understand the spread between the paper price and the physical reality.

Why Basis Matters More in China Than Elsewhere

In many developed markets, the convergence of futures and spot prices is driven largely by cost-of-carry models and interest rates. In China, the dynamic is heavily influenced by regional logistics, government inventory policies, and the sheer speed of supply chain adjustments. The "basis"—defined as the Spot Price minus the Futures Price—is often the leading indicator of supply tightness or glut before it reflects in the headline price.

When you trade Chinese commodity futures, you are not just betting on the direction of the market; you are betting on the relationship between physical availability and paper speculation. A widening positive basis (spot higher than futures) typically signals immediate physical tightness, often preceding a squeeze in the near-month contract. Conversely, a deep negative basis (futures trading significantly above spot) suggests a glut or excessive optimism that often leads to a mean-reversion drop.

The Mechanics of the Spread

Before diving into the reports, let’s ground this in contract specs. Take Rebar (RB) on the SHFE. The contract size is 10 tons per lot. The tick size is 1 yuan per ton. This means a 1-tick move in the spread is 10 CNY per lot. Now, look at Iron Ore (I) on the Dalian Commodity Exchange (DCE). The contract size is 100 tons. The tick size is 0.5 yuan per ton. That’s 50 CNY per lot per tick. When you are analyzing basis, you are looking for divergences that exceed these noise levels consistently.

The key takeaway: The basis is not static. It breathes. It expands and contracts based on warehouse receipt activity. If you ignore the warehouse stock report, you are trading blind in a market where physical delivery is a very real, very costly, and very visible event.

Decoding the Weekly Warehouse Stock Reports

The exchanges—SHFE, DCE, and ZCE (Zhengzhou)—publish weekly warehouse stock reports. These are not just dry PDFs; they are maps of market stress. When analyzing these reports for trades like trade rebar or copper, you need to look beyond the total number.

1. The Velocity of Change

A static inventory number tells you little. A rapid change tells you everything. If total warehouse stocks for copper on the SHFE drop by 15% week-over-week, while the futures price remains flat or rises slightly, this is a classic "inventory drain" signal. The physical market is being absorbed faster than the futures market is pricing in. This often sets up a long basis trade (Long Near-Month, Short Far-Month) or a directional long if the trend supports it.

Conversely, if stocks accumulate rapidly while prices hold steady, it indicates that the physical market is rejecting higher prices. Producers are dumping inventory into the futures market via warehouse receipts. This is a sell signal for the near-term basis.

2. Regional Dislocations

China is vast. A warehouse stock report is aggregated, but the underlying reality is regional. For agricultural commodities on the ZCE, such as soybean meal or corn, regional basis is critical. If stocks are piling up in Northeast China (harvest season) but declining in South China (consumption hubs), the regional spread widens. While retail traders may not easily trade regional arbitrage directly due to logistical barriers, this data informs the directional bias of the national contract. A decline in consumption-hub stocks supports a bullish bias even if national totals are stable.

3. Warehouse Receipts vs. Available Stocks

Pay close attention to the distinction between "Available Stocks" and "Warehouse Receipts." Only registered warehouse receipts can be used for delivery. Sometimes, total inventory looks high, but the percentage of registered receipts is low. This creates a "fake" supply glut. If the price of the futures contract dips because of perceived high inventory, but the number of available receipts is critically low, shorts are vulnerable to a delivery squeeze. This was a key driver in various squeeze events in the Chinese commodity futures landscape over the past decade.

Practical Application: Building a Basis Trading System

So, how do you turn this data into a trade? You don't need to be a logistics expert. You need a rule-based approach to interpreting the divergence.

Rule 1: The Mean Reversion Play

Calculate the historical average basis for your chosen contract over the last 12 months. When the current basis diverges more than 2 standard deviations from this mean, look for a reversion trade.

• Scenario: Iron Ore futures are trading 15% above spot (deep negative basis), and weekly warehouse stocks are rising.
• Logic: The market is overpriced relative to physical reality. Inventory is building, meaning supply is ample.
• Action: Short the futures contract or enter a spread trade (Short Near, Long Far) to capture the convergence. As the week progresses and stock data confirms the glut, the basis should tighten.

Rule 2: The Momentum Breakout

When warehouse stocks hit multi-year lows, and the basis is positive (Spot > Futures), the physical market is screaming for supply.

• Scenario: Rebar stocks fall for four consecutive weeks to historical lows. The spot market in major hubs is showing premium pricing.
• Logic: Short-covering is likely. Industrial buyers are forced to buy futures to lock in supply because physical availability is scarce.
• Action: Long the front-month contract. The tightness in physical delivery forces the futures price to rally to incentivize producers to deliver.

Rule 3: Filtering Noise with Volume

Do not act on inventory changes alone. Correlate the change with open interest (OI). If stocks drop but OI also drops, it suggests short covering rather than new buying. This is a weaker bullish signal. If stocks drop and OI rises, it indicates new money entering the market to bid up prices due to physical scarcity. This is a high-conviction bullish signal.

Risk Management and Contract Specifics

Trading China futures requires a robust risk framework. The leverage is high, and the volatility can be extreme. For example, during the 2021 energy and commodity rallies, daily swings in contracts like thermal coal and coke were massive. While we focus on metals and agri here, the principle remains: respect the volatility.

Always account for the commission and exchange fees in your basis calculations. A 50 CNY spread movement on Iron Ore is 50 CNY gross, but after commissions and slippage, your net edge might be 30 CNY. If your thesis only accounts for a 20 CNY move, you are trading at a loss.

Furthermore, be aware of the "Delivery Month" effect. As the delivery month approaches, the basis must converge to zero (theoretically). If you are holding a position into the delivery month, the mechanics of the warehouse report become even more critical. A sudden surge in warehouse receipts in the delivery month can cap upside potential, as shorts can easily deliver into the market.

Testing Your Edge Before Going Live

Reading about basis trading is one thing; executing it under pressure is another. The psychological weight of seeing your position diverge from the physical data, even when your logic is sound, can lead to premature exits. Many traders fail not because their analysis was wrong, but because they couldn't handle the drawdown while waiting for the basis to converge.

This is why rigorous testing is non-negotiable. You need to know if your rules for interpreting warehouse stocks actually yield a positive expectancy over 100+ trades. You need to verify that your stop-losses are wide enough to handle the noise of daily inventory fluctuations but tight enough to protect your capital when the trend breaks.

If you are serious about mastering Chinese commodity futures, you need a platform that simulates this environment accurately. While you can paper trade on various broker platforms, few offer the structured evaluation process that mirrors the discipline of professional trading. At XS Select, we provide a futures evaluation framework designed to test your ability to interpret market data and manage risk in the volatile China futures market.

Our evaluation environment allows you to apply these basis trading strategies against real market data, ensuring that your system is robust before you risk real capital. You can start testing your edge with our evaluation plans starting from $29. It’s a low-cost way to validate your understanding of warehouse reports and basis mechanics without the financial stress of live trading. Once you pass, you gain access to funded accounts, allowing you to trade with capital that is not your own, preserving your personal risk. But remember, the goal is not just to pass; it is to prove to yourself that your interpretation of the data is consistent and profitable.

Closing Thoughts

Basis trading in China is not for the faint of heart, nor is it for the casual observer. It requires a deep respect for the physical supply chain and the ability to read data that others ignore. The weekly warehouse stock report is your cheat sheet, but only if you know how to read it. Stop chasing the green candle. Start looking at the inventory. When the physical market speaks, the futures market eventually listens. Your job is to hear it first.