Copper reached a record $14,875 per tonne on 10 September, but one of the participants normally associated with a breakout of that magnitude had been moving in the opposite direction immediately beforehand. In the week to 4 September, LME Investment Funds reduced net length by 2,498.44 lots, cutting longs and adding shorts simultaneously. Copper then accelerated to its record before reversing sharply later on 10 September, when Reuters reported that the White House was hesitating over proposed tariffs on refined copper because of concerns about costs for US manufacturers. Benchmark LME copper fell to around $14,330/t after the report.
The sequence matters. The positioning snapshot cannot tell us what funds did during the subsequent breakout; it tells us that investment funds entered it less bullish than they had been a week earlier. The rapid reversal following the tariff report then provides a second clue about what had been supporting the price.
The underlying supply constraint is real. Grasberg remains impaired and Kamoa-Kakula's production outlook has been reduced. But refined copper has also been pulled towards the United States by tariff expectations while China is showing increasing resistance to record prices. The supply thesis is strong. Demand and positioning confirmation are less so.
TL;DR
- Three-month LME copper reached a record $14,875/t on 10 September, before falling roughly 3% to around $14,330/t after Reuters reported that the White House was hesitating over refined-copper tariffs.
- Six days earlier, LME Investment Funds had reduced net length by 2,498.44 lots, or 5.2%, to +45,817.21 lots.
- Funds cut 953.45 longs while adding 1,544.99 shorts — deterioration on both sides of the book.
- Grasberg remains a material supply constraint, while Kamoa-Kakula's latest 2026 production guidance has been reduced to 290,000–310,000 tonnes.
- US tariffs already apply to many copper articles, but refined copper itself remains under review. The market reaction on 10 September shows that expectations around that decision had become material to pricing.
- Chinese national copper inventory fell to 87,500 tonnes, but part of the draw was supply-led rather than evidence of stronger consumption.
- Chinese physical premiums are weakening and SMM expects national inventory to rebuild slightly as arrivals recover.
- Copper's record therefore reflects genuine supply constraints amplified by geographical dislocation, while neither investment-fund positioning nor Chinese demand provided clean confirmation entering the breakout.
Funds Were Becoming Less Bullish
| Investment Funds | 28 Aug | 4 Sep | Change |
|---|---|---|---|
| Long | 71,629.45 | 70,676.00 | −953.45 |
| Short | 23,313.80 | 24,858.79 | +1,544.99 |
| Net | +48,315.65 | +45,817.21 | −2,498.44 |
Source: London Metal Exchange Commitments of Traders reports. Positions reported in lots.
The mechanics matter more than the 5.2% decline in net length. Investment funds reduced existing longs while establishing additional short exposure, so both sides of the book moved in a less bullish direction. That is a progression from the previous week, when fund net positioning had fallen by only 364.54 lots. By 4 September, investment funds were showing a clearer deterioration in conviction.
Six days later, copper reached $14,875/t.
The reporting dates prevent us from claiming funds were selling during the breakout. The narrower conclusion is more defensible: the broad LME Investment Funds category entered the record-breaking move less bullish than it had been a week earlier. The record was therefore not preceded by a straightforward expansion in fund long positioning.
The Supply Constraint Is Real
That does not make the rally purely speculative.
Freeport-McMoRan's Grasberg disruption has been affecting the copper balance since September 2025. Freeport subsequently estimated that 2026 copper and gold production from PT Freeport Indonesia could be approximately 35% below pre-incident expectations, with recovery extending into 2027. For an asset of Grasberg's scale, that is a material loss of expected supply.
Kamoa-Kakula adds a separate constraint. Ivanhoe Mines originally expected 2026 production of 380,000–420,000 tonnes. Following the 2025 flooding and a revised mine plan, guidance was reduced and in July tightened again to 290,000–310,000 tonnes.
Chile adds the longer-duration problem: mature assets, declining grades and the capital intensity of replacement capacity constrain how quickly the world's largest copper-producing country can respond to higher prices.
These are different problems with different recovery profiles. Together, however, they establish that copper's supply constraint is not merely a product of financial positioning.
The US Has Changed Where Copper Sits
The refined market has also become geographically distorted. Large quantities of copper have been drawn towards the United States as traders and industrial consumers respond to US pricing and the possibility of future tariffs on refined copper.
A tonne held in America because its future relative value may increase is still part of global inventory, but it is not necessarily part of the metal readily available to consumers elsewhere. Copper can therefore be globally supplied and regionally tight at the same time.
US copper policy is only partly settled. Section 232 tariffs already apply to a range of semi-finished copper products and derivatives. Refined copper, including cathodes, was excluded from the initial measures, with a subsequent review considering tariffs of 15% from 2027 and 30% from 2028. Those future rates have not been imposed.
That distinction became market-moving on 10 September. Reuters reported that the White House was hesitating over refined-copper tariffs because of concerns that higher copper costs would hurt US manufacturers. Benchmark three-month LME copper fell around 3% to $14,329.50/t after having reached a record $14,875 earlier in the session. The US premium also fell sharply, temporarily making shipments towards the US uneconomic.
The reaction does not establish that tariff expectations caused the entire rally. Grasberg, Kamoa-Kakula and broader mine-supply constraints exist independently of US policy. But it provides a useful stress test.
Copper had been flowing towards the United States partly because traders anticipated a potential 15% refined-copper tariff from 2027. When the probability of that outcome appeared to weaken, both copper itself and the premium for sending metal to the US fell sharply. That suggests part of copper's record price represented a geographical-dislocation premium layered on top of genuine supply scarcity.
China Is Not Chasing the Price
China provides the strongest counterweight to the record.
SMM reported national mainstream copper inventory at 87,500 tonnes on 10 September, down 1,400 tonnes week on week and 56,800 tonnes below the same period last year. But the composition of that draw matters. Shanghai inventory increased as domestic arrivals improved while weak consumption slowed warehouse withdrawals, and Jiangsu and Guangdong destocked partly because arrivals declined. The national draw was therefore partly supply-led rather than demand-led.
Spot premiums tell the same story. Shanghai's average #1 cathode premium fell 45 yuan/t to 85 yuan/t on 10 September, with downstream users buying only as needed because outright copper prices were high. In Guangdong, high-quality copper ended 10 September at 250 yuan/t and standard copper at 150 yuan/t, both 70 yuan/t below the comparable 3 September readings.
SMM now expects national inventory to rebuild slightly as domestic and imported arrivals improve while downstream price acceptance remains weak.
That is an important test of the rally. Low Chinese inventory remains supportive, but low inventory caused partly by constrained arrivals is different from inventory being drawn rapidly by consumers competing for metal. At $14,000-plus copper, Chinese buyers are showing resistance rather than urgency.
Supply Is Confirming. Demand Is Not — Yet
The apparent contradiction is therefore manageable.
Copper reached a record while mine supply remained constrained and refined metal was geographically distorted towards the United States. It then reversed sharply when the market received evidence that one mechanism supporting that distortion — the prospect of US refined-copper tariffs — had become less certain.
At the same time, LME Investment Funds entered the breakout less bullish, Chinese physical premiums weakened and part of China's latest inventory draw resulted from reduced arrivals.
That does not invalidate the underlying copper thesis. It identifies what has been driving the marginal price. The strongest evidence currently sits on the supply and availability side, rather than in broad confirmation from speculative positioning or Chinese end demand.
That distinction matters because the two forms of support behave differently. Mine disruption can persist for years. Geographical dislocation can unwind much faster if tariff expectations or regional arbitrage change, and the 10 September reversal provided an early demonstration of exactly that.
The next phase therefore requires confirmation. If Chinese premiums strengthen while inventories continue falling and investment funds rebuild long exposure, the record will have developed a broader foundation. If Chinese inventories rebuild, premiums continue weakening and funds remain cautious, copper will increasingly look like a structurally tight market whose immediate price moved ahead of its marginal buyers.
Outlook
Base case: Copper remains supported by genuine mine-supply constraints and geographically restricted refined-metal availability, but record prices continue to suppress Chinese procurement. Investment-fund positioning entering the breakout provides no evidence that speculative conviction was strengthening alongside price.
Upside risk: Further mine disruption, slower recovery at Grasberg or Kamoa-Kakula, or a US decision to impose meaningful refined-copper tariffs after all would tighten available supply further. Stronger Chinese premiums combined with renewed fund accumulation would broaden confirmation.
Downside risk: Tariff expectations continue unwinding following the 10 September report, Chinese inventories rebuild as SMM expects and physical premiums keep falling. Improved mine output or stronger secondary supply would add further pressure.
What would change the view: Firmer Chinese premiums and procurement alongside continued inventory draws and renewed LME fund accumulation would show demand and positioning catching up with supply. Continued inventory rebuilding, weaker premiums and further fund liquidation would strengthen the opposite interpretation.
Key Risks
- The 4 September COTR cannot establish fund behaviour during the 10 September breakout or the reversal that followed it.
- Investment Funds are not synonymous with all speculative or systematic market participants.
- Grasberg and Kamoa-Kakula recovery schedules remain uncertain, and both have already been revised.
- Estimates of the size of the 2026 copper deficit vary materially between forecasters.
- China's low inventory can overstate demand strength when reduced arrivals contribute to destocking.
- Future US tariffs on refined copper remain undecided. The 10 September report indicates hesitation rather than a final outcome.
- Geographical scarcity can unwind faster than underlying mine scarcity, as the 3% single-session reversal demonstrated.
Intelligence Monitoring Points
- Next LME COTR: whether funds rebuilt exposure after 4 September, and how they responded to the record and reversal.
- Chinese national inventory: currently 87,500 tonnes, with SMM expecting a slight build.
- Shanghai and Guangdong spot premiums: currently 85 yuan/t, and 250 and 150 yuan/t respectively.
- US refined-copper tariff decision: whether the hesitation reported on 10 September becomes a formal deferral or reversal.
- The US premium: whether shipments towards the United States remain uneconomic after the reported collapse.
- Grasberg's recovery timetable against the 2027 target.
- Kamoa-Kakula performance against 290,000–310,000 tonne guidance.
FAQ
Did investment funds sell copper while it hit a record? The available data cannot establish that. Fund positioning is measured on 4 September; copper reached $14,875/t six days later. The finding is that funds entered the breakout less bullish than a week earlier.
Why did copper fall after setting a record? Reuters reported on 10 September that the White House was hesitating over proposed tariffs on refined copper because of concerns about costs for US manufacturers. Benchmark LME copper fell around 3% to $14,329.50/t, and the US premium fell sharply enough to make shipments towards the US temporarily uneconomic.
Is the copper supply shortage real? There are genuine supply constraints. Grasberg's disruption materially reduced expected production, while Kamoa-Kakula's 2026 guidance has been cut substantially from its original 380,000–420,000 tonne range.
Has the US imposed tariffs on refined copper? Not currently. Tariffs apply to many semi-finished copper articles and derivatives, but a possible 15% tariff on refined copper from 2027 and 30% from 2028 remains subject to a separate decision, which the 10 September report suggests is being reconsidered.
Is China confirming the rally? Not cleanly. Inventory remains low, but part of the latest draw was supply-led. Physical premiums are falling and SMM expects inventory to rebuild slightly as arrivals recover.
What matters most now? Whether demand begins confirming scarcity. Stronger Chinese premiums, continued destocking and renewed fund accumulation would make the record substantially more convincing.
Data and source note: LME Investment Fund positioning uses official London Metal Exchange Commitments of Traders reports for positions as at 28 August and 4 September 2026. Price and market-reaction evidence for 10 September 2026 uses contemporaneous market reporting. Chinese inventory and physical-market evidence uses Shanghai Metals Market releases through 10 September. Mine-supply evidence uses company disclosures from Freeport-McMoRan and Ivanhoe Mines. US tariff analysis distinguishes existing Section 232 measures covering copper products from the unresolved review of possible future tariffs on refined copper.
Sources
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.