China Metals Intelligence — The Physical Signal Strengthens

A week ago, China's metals market was showing upstream scarcity without convincing downstream confirmation. The latest SMM data move that argument forward: copper spot premiums have reversed sharply, zinc visible inventory is almost 21% below late August and parts of the aluminium chain have begun destocking. But the evidence remains fragmented, with national copper inventory rising slightly, billet historically abundant, cast aluminium alloy accumulating for a sixth consecutive week and SMM still describing underlying zinc order growth as limited.

TL;DR

• China's mainstream copper social inventory rose 1,600 tonnes week on week to 89,100 tonnes, but remains 44,600 tonnes below the 133,700 tonnes recorded a year earlier. Shanghai and Guangdong destocked while Jiangsu built.
• The larger copper development is in Guangdong, where high-quality cathode premiums reached RMB700/t, up RMB450/t week on week; standard copper RMB550/t, up RMB400/t; and SX-EW copper RMB490/t, also up RMB400/t. Contract rollover contributed, but SMM also points to tightening available supply.
• Zinc inventory fell to 213,500 tonnes, down 4,700 tonnes from 10 September and 9,000 tonnes from 14 September. The path was not continuous — stocks first built from 218,200 to 222,500 tonnes — but the broader decline from roughly 270,000 tonnes in late August is approximately 56,500 tonnes, or 20.9%.
• Roughly 16% of that entire three-week draw occurred in the final three days, which is a sharp acceleration rather than steady erosion.
• Zinc concentrate treatment charges are below −RMB2,000 per metal tonne domestically and −$120/dmt for imported concentrate, even though SMM says underlying downstream-order growth remains limited.
• Aluminium remains fragmented. Primary ingot recorded a 26,000-tonne daily draw across three key markets, while billet edged 500 tonnes lower week on week to 152,500 tonnes but remains at a four-year seasonal high. Cast aluminium alloy moved the other way, rising 500 tonnes to 34,600 tonnes, its sixth consecutive weekly build.
• Aluminium billet processing fees crossed back above zero in Foshan. φ90 rose from approximately −RMB50/t to +RMB160/t, while φ120 moved from approximately −RMB100/t to +RMB110/t.
• Nickel provided a smaller positive signal: SMM #1 refined nickel reached RMB125,400/t, up RMB2,200/t day on day, while the Jinchuan #1 premium increased RMB400/t to RMB4,250/t.
• The Chinese physical signals are strengthening just as LME Investment Funds become more defensive. Copper net length fell 5,233.83 lots, aluminium 2,481.69 lots and zinc 3,521.69 lots. Zinc is particularly notable because Investment Funds account for 31.45% of long open interest and 16.51% of short, the largest fund footprint on both sides among the six metals tracked here.

The Signal Board

Source: Shanghai Metals Market, data through 17 September 2026. Inventory definitions differ by product, geography and methodology and should not be aggregated or directly compared.

The board is materially different from a week ago, when upstream inventories were tight but several downstream and spot indicators were weakening. Copper premiums have now reversed, zinc has extended its broader late-August draw and aluminium billet has stopped building for the moment. At the same time, the cast-alloy series shows that improvement has not spread uniformly through the aluminium chain. The question is therefore no longer simply whether inventories are low, but where physical scarcity is actually reaching downstream markets.

Copper: The Premium Reversal Arrives

Last week's copper signal was uncomfortable for a bullish physical interpretation. National mainstream inventory had fallen to 87,500 tonnes, but Shanghai's average #1 cathode premium had dropped to RMB85/t. In Guangdong, high-quality and standard premiums stood at RMB250/t and RMB150/t respectively, both RMB70/t below the previous Thursday. SMM expected national inventory to rebuild slightly as arrivals recovered.

That rebuild arrived. Nationwide mainstream copper inventory stood at 89,100 tonnes on 17 September, up 1,600 tonnes week on week from 87,500 tonnes. The absolute level nevertheless remains low relative to last year, sitting 44,600 tonnes below the 133,700 tonnes recorded in the comparable 2025 period. More importantly, the national increase conceals regional divergence. Shanghai and Guangdong destocked, while increased domestic arrivals caused Jiangsu inventory to rise.

The larger change occurred in the spot market. Guangdong high-quality cathode was quoted at a RMB700/t premium, up RMB450/t from the previous Thursday. Standard copper reached RMB550/t, up RMB400/t, while SX-EW copper reached RMB490/t, also up RMB400/t. Some of that increase reflects the completion of contract delivery and rollover, which changed the futures basis against which physical premiums were quoted, so the entire weekly increase cannot be interpreted as a sudden acceleration in end demand. SMM nevertheless also attributes the move to continuously tightening available supply.

Guangdong warehouse inventory fell to 7,200 tonnes, down 800 tonnes week on week, while warrants declined by 451 tonnes to only 325 tonnes. SMM reported weekly arrivals of 11,200 tonnes, down 2,700 tonnes, against warehouse withdrawals of 13,300 tonnes, down 372 tonnes. Those flow figures imply a larger net movement than the reported 800-tonne inventory decline and should not be mechanically reconciled: the series may differ in timing, warehouse coverage or measurement basis. The useful signal is therefore directional rather than an attempt to construct an inventory balance from separately reported SMM flow data.

Consumption was subdued around contract rollover before improving later in the week. SMM expects domestic and imported arrivals into Guangdong to remain low, while consumption improves from this week's level, leaving local inventory under further downward pressure. Nationally, it expects a slight destock next week as arrivals stabilise and essential restocking improves modestly.

This means copper has passed one of the tests identified in last week's China Metals Intelligence: spot premiums have strengthened rather than weakening further. It has not passed the broader demand test. National inventory rose, and supply constraints account for an important part of Guangdong's tightness. But the combination of low local stocks, limited arrivals and buyers accepting substantially higher premiums means the physical signal is materially stronger than it was seven days ago.

Copper Versus LME Funds

That shift has occurred while Investment Funds have been reducing LME copper exposure. In the week to 11 September, fund net length fell 5,233.83 lots to +40,773.38. Long positions declined 5,692.43 lots to 64,969.57, while shorts fell only 458.60 lots to 24,196.19. The reduction was therefore overwhelmingly long liquidation rather than aggressive new short-building.

Chinese spot conditions have subsequently moved in the opposite direction at the margin. This does not establish that one market is right and the other wrong: LME investment positioning reflects portfolio exposure, macro expectations and risk management, while Guangdong premiums measure the immediate availability and price of particular grades of physical cathode. What it does establish is a divergence worth monitoring. Funds have been reducing copper exposure while available metal in an important Chinese consuming market has become materially more expensive to secure.

The next test is whether that separation persists. If Guangdong premiums remain elevated after contract-roll effects dissipate and national inventory resumes falling while LME funds continue liquidating longs, the divergence between financial positioning and Chinese physical availability would become more significant.

Zinc: A 21% Three-Week Draw, But Not a Straight Line

Zinc remains the strongest sustained inventory story in the Chinese base-metals complex, but the path has been less orderly than the headline three-week decline suggests. SMM's seven-region zinc ingot inventory stood at 218,200 tonnes on 10 September, subsequently built by 4,300 tonnes to 222,500 tonnes on 14 September, and then fell 9,000 tonnes over the following three days to 213,500 tonnes on 17 September. The latest level is therefore 4,700 tonnes below 10 September, but that weekly comparison contains a meaningful mid-period rebuild and subsequent sharp draw.

The broader trend remains substantial. SMM's own analysis frames the movement from approximately 270,000 tonnes in late August to 213,500 tonnes now, equivalent to a reduction of roughly 56,500 tonnes, or 20.9%. The significance lies in the cumulative reduction rather than an assumption that stocks have declined smoothly every day. It is also worth noting the concentration: the 9,000 tonnes removed between 14 and 17 September represent roughly 16% of the entire three-week decline, compressed into three days. Read alongside the preceding build, that describes a market moving in sharp bursts rather than eroding steadily, and the most recent burst was the largest in the series.

Raw-material conditions reinforce the physical story. Domestic zinc concentrate treatment charges have fallen below −RMB2,000 per metal tonne, while imported concentrate TCs are below −$120/dmt. Negative treatment charges of that magnitude indicate intense competition among smelters for concentrate. Tight raw-material availability and seasonal maintenance have also constrained refined production, while trade flows are removing some of the domestic cushion: the refined-zinc import window has remained closed as overseas prices outperform domestic prices, while a lower SHFE/LME price ratio has encouraged exports into Southeast Asia.

The important qualification remains demand. SMM continues to describe underlying downstream-order growth as limited. Zinc's inventory decline therefore cannot simply be read as evidence of booming galvanising or end-use activity. The current tightening is being driven by a combination of concentrate scarcity, refined-production constraints, trade flows and consumption.

That distinction makes the latest LME positioning unusually interesting. Investment Funds reduced zinc net length by 3,521.69 lots to +59,123.26 in the week to 11 September. Longs slipped only 216 lots to 124,508.26, while shorts increased 3,305.69 lots to 65,385.00. The change was therefore overwhelmingly a new-short story.

The scale of fund participation gives that move additional weight. Investment Funds represented 31.45% of zinc long open interest and 16.51% of short open interest, the largest fund footprint on both sides among the six LME metals tracked by Bloodstone. Zinc is consequently the metal in this comparison where investment-fund positioning matters most, and funds are adding shorts while Chinese visible refined inventory sits almost one-fifth below late-August levels and concentrate treatment charges remain deeply negative.

That is a sharper divergence than inventory alone suggests. It still has a plausible fundamental explanation: weak downstream-order growth gives investors reason to question whether current physical tightness can persist. The question is whether demand remains weak long enough for stocks to rebuild before raw-material scarcity and trade flows remove more of the refined cushion.

Aluminium: Three Inventory Signals, Three Different Stories

Aluminium has become the clearest example of why a single inventory series cannot be used as a proxy for the entire Chinese metals chain. SMM reported a 26,000-tonne daily draw in primary aluminium ingot across three key markets on 17 September, with all three destocking. This should not be confused with SMM's broader national primary-ingot social-inventory series, which covers eight major markets. A directly comparable 17 September national absolute level is not available in the accessible release, so the three-market daily draw is best treated as a directional observation rather than a national inventory total.

The downstream picture is mixed. Aluminium billet inventory stood at 152,500 tonnes, down only 500 tonnes from Thursday 10 September, although it had fallen 5,000 tonnes from Monday 14 September. The decline is notable because billet had been accumulating since mid-August, and warehouse withdrawals improved to 38,900 tonnes during 7–14 September, up 2,800 tonnes week on week. Lower outright aluminium prices improved purchasing willingness, while maintenance-related production cuts among Guangxi billet producers reduced expected supply.

The absolute billet level nevertheless remains exceptionally high. Stocks are 17,500 tonnes above the comparable 2025 level, 31,000 tonnes above 2024 and 61,000 tonnes above 2023, leaving inventory at its highest level for this point of the year in four years. A 500-tonne weekly decline therefore marks a change in direction, not yet a meaningful digestion of the accumulated downstream stock.

Cast aluminium alloy provides an additional counter-signal. Social inventory rose 500 tonnes week on week to 34,600 tonnes, extending the buildup to a sixth consecutive week since early August, although the pace of accumulation slowed. Jiangsu inventory increased by 1,500 tonnes, while the other five monitored regions collectively fell by 1,200 tonnes, including an 800-tonne decline in Guangdong. The regional split again matters, but the national product-level signal remains one of continued accumulation.

Processing fees show another change that is easy to miss if only the absolute level is considered. SMM A00 aluminium fell from RMB24,560/t on 10 September to RMB24,180/t on 17 September, a decline of RMB380/t, improving downstream purchasing economics. In Foshan, φ90 billet processing fees increased RMB210/t to +RMB160/t, implying a previous level of approximately −RMB50/t. φ120 fees also increased RMB210/t to +RMB110/t, from approximately −RMB100/t. Both therefore crossed from negative to positive in a week. A negative processing fee means the quoted conversion spread had inverted, with billet priced below the ingot from which it is made; fees have now moved back above zero.

Wuxi φ90 processing fees reached RMB400/t and φ120 RMB300/t, while Nanchang reached RMB280/t and RMB200/t respectively. SMM still describes Foshan and Nanchang fees as historically low, so the sign change should not be mistaken for normalisation. It does, however, represent a more meaningful threshold than describing the move merely as a sharp rebound.

Taken together, aluminium is not delivering a single directional message. Primary ingot is drawing in key markets; billet has begun to decline but remains exceptionally abundant; cast alloy continues to accumulate; and billet processing economics have crossed back above zero as outright metal prices fall. The downstream test identified last week has therefore begun to move, but it has not been passed.

Aluminium Versus LME Positioning

Investment Funds reduced aluminium net length by 2,481.69 lots to +147,601.71 in the latest reporting week. Longs declined only 225.51 lots to 186,017.82, while shorts increased 2,256.18 lots to 38,416.11. Unlike copper, aluminium's reduction in net exposure was therefore predominantly a new-short move.

The Chinese physical evidence does not provide a simple rebuttal. Rapid primary-ingot draws and the return of positive billet processing fees are supportive, but historically high billet inventory and a sixth consecutive increase in cast-alloy stocks leave ample evidence of downstream softness. The distinction is important: tighter primary availability can coexist with weak or uneven demand further along the fabrication chain.

That makes aluminium less a clean financial-versus-physical divergence than a diagnostic split within the physical market itself. The next significant signal would be sustained billet destocking alongside an end to the cast-alloy accumulation. Until then, upstream tightness should not be extrapolated into a broad Chinese aluminium-demand acceleration.

Nickel: A Smaller Signal, Moving With the Funds

Nickel remains the least developed physical tightening argument among the four metals examined here, but the latest SMM readings have strengthened at the margin. On 17 September, the average SMM #1 refined nickel price reached RMB125,400/t, up RMB2,200/t day on day, while the average Jinchuan #1 refined nickel premium increased RMB400/t to RMB4,250/t. That compares with a Jinchuan premium of around RMB2,300/t on 10 September.

There has also been a modest downstream improvement. Stainless-steel social inventory across Wuxi and Foshan stood at 923,800 tonnes, down from 926,200 tonnes on 10 September, a decline of approximately 0.26% week on week. SMM attributes the movement to lower-price restocking, modest reductions in stainless-mill production schedules and declining futures warrant inventory, while cautioning that peak-season rigid demand has not fully recovered.

One week of stronger refined pricing, a higher Jinchuan premium and a 0.26% stainless inventory decline are not sufficient to establish a broader nickel tightening cycle. They are nevertheless directionally consistent with LME positioning. Nickel was the only one of the six metals in which Investment Funds increased net bullish exposure in the latest COTR: net length rose 1,129.79 lots to +16,286.74, with longs increasing 2,926.09 lots to 49,582.53 and shorts increasing 1,796.30 lots to 33,295.79.

That alignment should be read with one qualification. Funds hold 15.21% of nickel long open interest against 10.21% of short, the narrowest spread between the two sides of any net-long metal in the complex, and well inside zinc's 31.45% and 16.51%. Nickel is therefore the market where financial positioning and Chinese physical indicators are pointing the same way, but also the one where fund conviction is least concentrated on either side. Whether it develops into something more substantial depends on Indonesian supply, refined Chinese inventory, stainless production and battery-sector demand — questions that require a broader nickel analysis rather than extrapolation from one week's SMM data.

A Stronger Physical Signal, Not a Broad Demand Recovery

The most important development since last week's China Metals Intelligence is not evidence of a broad Chinese metals-demand recovery. It is that several physical indicators which were previously missing have begun to move while others continue to resist the same interpretation.

Copper is the clearest change. The anticipated national inventory rebuild occurred, but Guangdong premiums reversed sharply as arrivals weakened and local availability tightened. Zinc's path has been volatile within the week, yet visible inventory is still almost 21% below late August and concentrate treatment charges remain deeply negative. Aluminium has become more complicated rather than simply stronger: primary ingot drew sharply in three key markets and billet processing fees crossed back above zero, but billet remains at a four-year seasonal high and cast-alloy inventory has accumulated for six consecutive weeks. Nickel has improved modestly, but not enough to support a structural conclusion.

The LME positioning adds another layer. Investment Funds reduced net exposure in five of the six metals tracked by Bloodstone in the week to 11 September. Copper's reduction came predominantly through long liquidation, while aluminium and zinc attracted substantial new shorts. Nickel was the exception, with net bullish exposure increasing.

China's physical evidence is not validating that defensive shift uniformly. Copper now provides the clearest financial-versus-physical divergence, while zinc combines the largest Investment Fund open-interest footprint in the complex with a three-week visible-inventory decline of almost 21%. Aluminium remains internally divided between upstream and downstream signals. Nickel is the one market where fund positioning and the latest Chinese physical indicators are moving broadly in the same direction.

The common conclusion remains narrower than a China recovery call. Available physical metal is tightening selectively while downstream demand remains uneven. The difference from a week ago is that the evidence of selective tightness has become harder to dismiss.

Outlook

Base case: Chinese base-metal conditions remain fragmented, with physical availability tighter than broad downstream-demand indicators imply. Copper national inventory remains historically low while regional availability stays constrained; zinc stocks remain vulnerable to concentrate scarcity, production limitations and trade flows; and aluminium primary tightness coexists with heavy downstream inventories.

Upside risk: Copper premiums remain elevated after contract-roll effects fade and national inventory resumes drawing; zinc falls towards or below 200,000 tonnes while concentrate conditions remain extreme; and aluminium billet begins sustained destocking alongside an end to the cast-alloy inventory build. That combination would provide materially stronger evidence that upstream tightness is propagating through the downstream chain.

Downside risk: Copper arrivals recover and spot premiums normalise quickly, zinc inventory rebuilds as the mid-September movement briefly demonstrated it can, and aluminium billet and cast-alloy stocks remain elevated after pre-holiday purchasing passes. That would strengthen the interpretation that current tightness is predominantly supply- and logistics-driven rather than the beginning of broad demand acceleration.

What would change the view: The strongest confirmation would be simultaneous improvement across physical availability and downstream consumption: sustained copper premiums after rollover effects dissipate, continued zinc destocking accompanied by stronger downstream orders, and meaningful aluminium billet and cast-alloy inventory reductions. Those conditions have not yet been met.

Key Risks

• Inventory movements are not direct measures of demand. Copper's Guangdong tightness partly reflects constrained arrivals and contract mechanics, while zinc's broader draw reflects concentrate scarcity, lower refined output and trade flows as well as consumption.
• Copper's spot move is partly mechanical. The completion of contract delivery and rollover changed the futures basis against which Guangdong premiums are quoted, so the full RMB400–450/t increase cannot be attributed to end demand.
• Copper tightness remains regional. National inventory rose even as Shanghai and Guangdong destocked, with Jiangsu building on higher domestic arrivals.
• Aluminium inventory series are not interchangeable. Primary ingot, billet and cast alloy cover different products and geographical universes and cannot be aggregated into a single stock measure.
• Billet remains historically abundant. A 500-tonne weekly decline does not reverse accumulation that has left stocks at a four-year seasonal high.
• Zinc's visible stock series moves in both directions quickly. The 9,000-tonne decline between 14 and 17 September followed a 4,300-tonne build earlier in the same period.
• Pre-holiday stocking can flatter withdrawals. Some copper and aluminium improvement may reflect purchasing ahead of the holiday, while lower outright aluminium prices can release demand that does not persist.
• Financial positioning is not a forecast of physical availability. LME Investment Fund exposure and Chinese spot conditions operate on different horizons; the value lies in identifying divergences and testing whether they persist.
• Nickel evidence remains preliminary. A one-day refined-price increase, a stronger Jinchuan premium and a 0.26% stainless destock are insufficient to establish structural tightening.

Intelligence Monitoring Points

• Copper national inventory, at 89,100 tonnes, and whether SMM's expected slight destock next week materialises.
• Guangdong copper inventory and arrivals, at 7,200 tonnes with weekly arrivals of 11,200 tonnes against a cited annual average of 14,000.
• Guangdong premiums, at RMB700/t high-quality, RMB550/t standard and RMB490/t SX-EW, and how much survives beyond contract-roll effects.
• Zinc inventory, at 213,500 tonnes against 222,500 on 14 September and roughly 270,000 in late August.
• Zinc treatment charges, below −RMB2,000 per metal tonne domestically and −$120/dmt imported, as the clearest measure of raw-material scarcity.
• Zinc fund positioning, given Investment Funds' 31.45% share of long open interest and 16.51% of short, the largest footprint in the complex.
• Aluminium billet inventory, at 152,500 tonnes, and whether the initial draw develops into sustained digestion.
• Cast aluminium alloy inventory, at 34,600 tonnes after six consecutive weekly builds, as the clearest downstream counter-signal.
• Foshan billet processing fees, after φ90 and φ120 crossed from approximately −RMB50/t and −RMB100/t to +RMB160/t and +RMB110/t.
• Nickel indicators, at RMB125,400/t for SMM #1 refined, RMB4,250/t for the Jinchuan premium and 923,800 tonnes of stainless inventory across Wuxi and Foshan.

FAQ

What changed most in China's metals market this week? Copper spot premiums. National inventory rose slightly to 89,100 tonnes, but Guangdong availability tightened and high-quality cathode premiums increased from RMB250/t to RMB700/t in a week. Contract rollover explains part of the move, while reduced arrivals and low local inventory provide an additional physical explanation.

Is Chinese copper demand now strong? Not conclusively. Consumption improved later in the week and buyers accepted higher premiums, but national inventory still increased and regional tightness partly reflects reduced supply. The physical signal has strengthened without establishing a broad demand acceleration.

Has zinc inventory fallen continuously since late August? No. The broader trend is sharply lower, from approximately 270,000 tonnes in late August to 213,500 tonnes on 17 September, but the path has not been uninterrupted. Inventory stood at 218,200 tonnes on 10 September, rose to 222,500 tonnes on 14 September and then fell 9,000 tonnes over the following three days — roughly 16% of the entire three-week draw compressed into that final stretch.

Why is LME zinc positioning particularly important? Investment Funds hold the largest share of both long and short open interest among the six metals tracked here, at 31.45% and 16.51% respectively. In the latest week they added 3,305.69 shorts even as Chinese visible inventory remained almost 21% below late August and concentrate treatment charges stayed deeply negative.

Is aluminium demand recovering? The evidence is mixed. Billet inventory has begun to fall and Foshan processing fees crossed back above zero, but billet stocks remain at a four-year seasonal high and cast aluminium alloy inventory has risen for six consecutive weeks. Primary ingot is showing tighter conditions in key markets without equivalent confirmation across the downstream chain.

Why aren't the primary aluminium ingot figures in the Signal Board? The available 17 September SMM observation reports a 26,000-tonne daily draw across three key primary-aluminium markets, while SMM's broader national primary-ingot social-inventory series covers eight markets. Without a directly comparable 17 September national absolute level, combining the two would risk conflating different inventory universes.

Is nickel beginning to tighten? There are early positive indicators: refined nickel rose to RMB125,400/t, the Jinchuan premium increased to RMB4,250/t and stainless inventory edged 0.26% lower. Those movements are directionally consistent with increased LME fund net length, though nickel also carries the narrowest gap between fund long and short open-interest shares of any net-long metal, so conviction on either side is comparatively thin.

What matters most next week? Persistence. Copper premiums need to remain firm after contract-roll effects fade; zinc needs to sustain the broader inventory draw without another substantial rebuild; and aluminium needs more meaningful billet destocking alongside a reversal in cast-alloy accumulation. Those would provide stronger evidence that physical tightness is spreading beyond isolated parts of the supply chain.

Data and source note: Shanghai Metals Market physical-market, inventory, spot-price and downstream-market reports through 17 September 2026. Copper nationwide inventory refers to SMM's mainstream monitored social inventory; zinc refers to SMM's seven-region inventory series. Aluminium primary ingot, billet and cast aluminium alloy are distinct products and inventory series with different geographical coverage and should not be aggregated. The reported 26,000-tonne primary-ingot draw refers to three key markets and is not presented as SMM's national eight-market inventory total. Percentage changes and implied prior processing-fee levels are Bloodstone Research calculations from reported SMM figures. LME Investment Fund positioning refers to London Metal Exchange MiFID II Weekly COTR reports for positions as at 11 September 2026, and covers the Investment Funds category, non-risk-reducing, reported in lots. Bloodstone Research preserves the exact figures published in each contemporaneous LME vintage rather than retrospectively replacing historical positions using later reported changes.

Sources

• Shanghai Metals Market
• London Metal Exchange

This document is published by Bloodstone Research for informational and institutional research purposes only. It does not constitute investment advice, an investment recommendation, an offer or solicitation to buy or sell any financial instrument, commodity or security, or a forecast of future performance. Market conditions and data may change without notice. Readers should conduct their own analysis and, where appropriate, seek independent professional advice before making investment decisions. For institutional enquiries contact research@bloodstonecapital.co.uk.