← Back to Blog · 2026-10-17 · 7 min read · Market Preview
Every Monday morning, while you are still navigating the weekend hangover, a specific group of traders in Shanghai and Shenzhen are already glued to their screens. They are not looking at price charts. They are not checking macroeconomic news. They are refreshing the weekly inventory reports from the Shanghai Futures Exchange (SHFE), Dalian Commodity Exchange (DCE), and various private data providers like Mysteel or SteelHome.
Why? Because in the world of Chinese commodity futures, supply and demand are not abstract concepts—they are physically measurable. Unlike US equities, where sentiment can drift for weeks disconnected from fundamentals, physical commodities like rebar, iron ore, and copper have a hard reality check: you cannot eat inventory, and you cannot build skyscrapers with imaginary steel.
For global retail traders, ignoring these reports is like trading without a compass. You might get lucky with momentum, but over time, the physical reality of warehouse stocks will crush your P&L. In this guide, we will strip away the academic noise and focus on how to actually use inventory data to generate high-probability setups in China futures markets.
The Distinction That Matters: Exchange vs. Social Inventory
The biggest mistake new traders make when analyzing China futures is treating all inventory data as equal. It is not. You must distinguish between Exchange-Registered Inventory and Social Inventory.
Exchange Inventory refers to goods physically stored in designated delivery warehouses approved by the exchange (SHFE, DCE, ZCE). This data is public, standardized, and released weekly (usually on Fridays or Mondays, depending on the commodity). It represents the "visible supply" that can immediately impact delivery obligations.
Social Inventory (also called "public stock" or "merchant stock") is estimated data collected by private agencies. It includes steel sitting in trading hubs, construction sites, and non-exchange warehouses. This data is messier, often revised, and lags slightly, but it provides a broader picture of true market supply.
Practical Rule: If you are trading near expiration, exchange inventory is king. If you are trading the mid-month or front-month contracts for directional trends, social inventory often leads the price action because it reflects the actual flow of goods into the real economy.
Iron Ore and Rebar: The Steel Chain Logic
To trade rebar futures (RB) or iron ore futures (I), you must understand the steel production chain. Iron ore is the raw material; rebar is the finished product. Inventory levels in this chain create specific trading signals.
Scenario A: The Compression Trade (Bullish)
Imagine you see social inventory of rebar falling for three consecutive weeks, while iron ore inventories at Chinese ports are also declining. This indicates that downstream demand (construction and manufacturing) is outpacing production. Mills are buying raw materials faster than they can sell finished goods, or they are running at full capacity to meet immediate orders.
- Signal: Buy Rebar (RB) or Buy Iron Ore (I).
- Contract Specs: Rebar (RB) trades on SHFE with a contract size of 10 tons per lot. The tick size is CNY 1 per ton. A 100-point move equals CNY 1,000 per lot. Iron Ore (I) trades on DCE with a size of 100 tons per lot. Tick size is CNY 0.5 per ton. A 10-point move equals CNY 500 per lot.
- Logic: Low inventory creates a "squeeze." If a major project suddenly ramps up demand, there is no buffer. Prices must rise to incentivize production and divert supply from other regions.
Scenario B: The Inventory Build (Bearish)
Conversely, if you see rebar social inventory rising while mill production rates remain high, it means supply is exceeding demand. This is common during China's rainy season (June–July) or winter holidays when construction slows down.
- Signal: Sell Rebar (RB). If iron ore inventories are also high, consider shorting Iron Ore (I) as mills may cut production to avoid losses.
- Watch Out: If inventory builds are accompanied by falling raw material prices, the margin squeeze on mills intensifies, often leading to production cuts. This can eventually floor the price, so use tighter stops.
Copper and Aluminum: The Global-Local Nexus
Non-ferrous metals like copper (CU) and aluminum (AL) are different. They are globally traded, but China dominates consumption. Here, SHFE warehouse inventory is a critical indicator of local liquidity and arbitrage opportunities.
When SHFE copper inventories drop sharply, it often signals a tightening of local supply relative to global stocks. This can lead to a "backwardation" in the local curve (near-term contracts trading higher than deferred contracts). For a trader, this is a strong signal to go long the front-month contract or enter a calendar spread (Long Near, Short Far).
However, be cautious of the "LME-Shanghai Arbitrage." If Chinese inventories are low but global LME stocks are high, the price disconnect may be temporary. Look for the CNY/USD exchange rate and import premiums. If the import premium is negative, it is cheaper to ship copper from London to Shanghai, which will eventually refill warehouses and cap prices.
Interpreting the Data: Context is Everything
Reading a number like "inventory down 50,000 tons" is meaningless without context. You must analyze the rate of change and the seasonality.
1. Rate of Change vs. Absolute Level
A drop in inventory is bullish, but a decelerating drop can be bearish. If inventory falls by 100k tons in Week 1, 80k in Week 2, and 20k in Week 3, the bullish momentum is fading. The market has already priced in the shortage. This is often a "buy the rumor, sell the news" opportunity.
2. Seasonal Adjustments
China has distinct seasonal cycles. The post-Chinese New Year period (February/March) typically sees a massive inventory build as production resumes but construction hasn't fully started. A sudden drop in inventory during this period is an extremely bullish signal, often marking the start of a new uptrend.
Pro Tip: Always overlay your inventory data with a 5-year seasonal index. If current inventory levels are in the bottom 10% of historical ranges for this time of year, the probability of a price rally increases significantly.
Executing the Trade: Contract Specs and Risk Management
Knowing the signal is only half the battle. Executing it requires precise knowledge of the contract specifications. One common error among global traders entering Chinese commodity futures is miscalculating position size due to the CNY currency denomination and leverage ratios.
| Commodity | Exchange | Ticker | Contract Size | Tick Size | Tick Value |
|---|---|---|---|---|---|
| Rebar Steel | SHFE | RB | 10 Tons | CNY 1.00 | CNY 10.00 |
| Iron Ore | DCE | I | 100 Tons | CNY 0.50 | CNY 50.00 |
| Copper | SHFE | CU | 5 Tons | CNY 10.00 | CNY 50.00 |
| Thermal Coal | ZCE | ZC | 100 Tons | CNY 0.20 | CNY 20.00 |
Note: Prices are quoted in CNY per ton. Always convert your P&L to your home currency in real-time, as the CNY/USD exchange rate can significantly impact your net return, especially for longer-term holds.
Common Pitfalls and How to Avoid Them
Even with perfect data, traders fail. Here are the top three traps when trading inventory reports:
1. Ignoring Policy Intervention
The Chinese government actively manages commodity prices. If inventory drops too low and prices spike dangerously (as seen during the 2021 thermal coal rally), the National Development and Reform Commission (NDRC) may intervene. This can include releasing strategic reserves, increasing import quotas, or even imposing price caps. Rule: If prices move more than 10% in a week on inventory news alone, be cautious. Policy risk rises exponentially with price velocity.
2. Lagging Data
Private social inventory data is often released with a 1-2 day lag. By the time you see the report, the smart money has already reacted. Use the data to confirm a trend, not to predict the immediate next tick. Combine inventory data with price action and volume for better timing.
3. Overleveraging
Chinese futures are highly leveraged. A 5% margin requirement means you control 20x your capital. A small move against you can wipe out your account. Always calculate your position size based on the tick value and your maximum risk per trade. Never trade inventory signals with more than 1-2% of your account equity at risk.
Practical Application: Building a Weekly Routine
Here is a streamlined workflow for integrating inventory analysis into your trading week:
- Friday Afternoon: Check SHFE/DCE weekly inventory reports. Note changes in exchange stocks. Compare against the previous week.
- Monday Morning: Review private agency reports (Mysteel/SteelHome) for social inventory updates. Look for divergences between exchange and social stocks.
- Tuesday: Identify top 3 commodities with the strongest inventory trends (e.g., falling stocks + rising prices). Check technical charts for support/resistance levels.
- Wednesday–Thursday: Execute trades based on confirmed signals. Use inventory trends to set stop-losses (e.g., place stop below recent support if inventory remains low).
- Friday: Review performance. Did the inventory signal hold? Adjust your model if necessary.
Test Your System Without Risking Capital
Understanding inventory data is a skill. Applying it profitably is a discipline. You might know that low rebar inventory is bullish, but can you manage the trade through the volatility that often accompanies low-stock squeezes? Can you stick to your stop-loss when the market whipsaws?
This is where rigorous testing matters. Before committing real capital to trade rebar or iron ore, you need to prove your strategy works under pressure. At XS Select, we provide a transparent China futures evaluation platform designed specifically for this purpose. You get access to real-time market data and realistic execution conditions to test your inventory-based strategies.
We believe that trust is built through performance, not promises. That is why our evaluation challenges start from as low as $29, allowing you to verify your edge with minimal upfront cost. Whether you are a beginner learning to read SHFE reports or a veteran refining your logic, you can test your system in a professional environment. No hidden fees, no fake guarantees—just honest feedback on your trading capability. Visit XS Select to start your evaluation and see if your inventory analysis translates into consistent execution.