LME Positioning Intelligence — Bears Leave Aluminium, Bulls Arrive in Zinc

Investment funds added almost identical amounts of net bullish exposure to aluminium and zinc in the week to 28 August. The similarity ends there. Four-fifths of aluminium's increase came from bears closing positions; zinc's came entirely from new buying, with shorts actually growing alongside. Copper and tin did not move at all, and lead remains a net short. Six metals, and the aggregate net position tells you very little about what actually happened in any of them.

TL;DR

• Investment funds are net long five of six LME base metals, totalling 252,582 lots across the complex.
• Aluminium leads at +148,946.20 lots after a +6,510.24 weekly increase — but 79.9% of that came from short covering, not new buying.
• Zinc added +6,073.80 to +61,051.69 through the opposite mechanic: longs rose 6,311.37 while shorts also grew 237.57.
• Copper was static at +48,315.65, down 364.54, despite a tightening physical market.
• Nickel added 1,697.88 to +16,132.57, mostly through new longs.
• Lead is the outlier and the only net short, at −24,433.07 and deepening.
• Tin is effectively dormant: +2,569.00 lots across only 100 holding entities.
• This week's report published Wednesday 2 September rather than Tuesday, delayed by the UK bank holiday on 31 August.

The Positioning Board

Source: LME Commitments of Traders reports, investment fund category, positions as of 28 August 2026. Reported in lots.

Aluminium and zinc added within 437 lots of each other.

Read the components and they are not the same trade at all.

Aluminium: The Short Base Shrinks

Aluminium holds the largest fund net long in the complex at +148,946.20 lots, and it grew by 6,510.24 last week.

The composition is the story. Outright longs rose just 1,307.03 lots. Shorts fell 5,203.21.

Short covering therefore accounted for 79.9% of the net increase.

That distinction matters because the two sources of buying behave differently.

Short covering is mechanically self-limiting. It requires no participant to hold a positive view — only to abandon a negative one. Once bearish positions are closed, the buying they generate stops, and it does not resume.

New long accumulation reflects capital actively committed to a directional thesis. It can continue for as long as conviction holds.

The relevant question for aluminium is therefore how much short base remains.

Fund shorts now stand at 41,337.68 lots, down 11.2% in a single week. Longs outnumber shorts 4.6 to one.

That is a considerably thinner cushion than a month ago. If the remaining shorts continue closing at last week's pace, the mechanical support behind aluminium's advance has a measurable end point.

The position is also almost entirely speculative. Risk-reducing exposure in the fund category amounts to four lots long and eight short against a total position of more than 231,000 lots. Some 307 separate fund entities hold aluminium, the largest participant count of any LME base metal.

Aluminium's underlying picture remains one of unusually thin exchange liquidity against a gradually improving global supply position. The fund move is consistent with bears concluding the liquidity constraint is not resolving quickly — not with a wholesale re-rating of the global balance.

Zinc: Fresh Capital Into a Tightening Market

Zinc produced the cleanest bullish signal in the complex.

Outright longs increased 6,311.37 lots to 120,063.54. Shorts rose 237.57 to 59,011.85.

Because shorts grew rather than shrank, new buying accounted for more than the entire net move of +6,073.80. Net length rose 11.0% in a single week.

This was not bears leaving. It was bulls arriving.

The scale of fund involvement is also unusual. Funds now hold 30.68% of total long open interest in zinc against 15.09% of the short side — nearly double their share in any other LME base metal. Some 299 fund entities hold a position. Risk-reducing exposure is 15 lots long and zero short.

The physical backdrop through the reporting period supports the move.

Three-month zinc reached $3,949.50/t on 26 August, its highest since June 2022, while the cash-to-three-month backwardation widened to $231.75/t on 27 August. LME warehouse stocks stood at 97,875 tonnes on 27 August, down 58% from the 234,100 tonnes held at the end of 2024.

The more revealing figure is what is actually available.

By 1 September, cancelled warrants had risen to 30,875 tonnes against total stocks of around 99,125 tonnes, leaving roughly 68,250 tonnes deliverable — under two days of consumption against ILZSG's 14.0-million-tonne 2026 demand forecast. Total inventory has edged higher; available inventory has not.

That is the distinction the market is pricing. Metal in a warehouse under a cancelled warrant is committed elsewhere.

Prices have since eased, with three-month zinc trading around $3,880/t on 3 September.

There is also a structural feature of the position that deserves attention.

Funds have become an unusually large part of the long side.

Investment firms and credit institutions are net short 29,475.29 lots and added 6,299.23 shorts last week. Commercial undertakings — the producers, merchants and fabricators who handle physical zinc — are net short 38,870.86 and reduced longs by 1,685.20.

Both categories leaned further short into a rising price.

Producers hedging forward sales at a four-year high is ordinary behaviour and not a bearish signal in itself. But the resulting structure is one-sided: a large and recently established speculative long, with the physical trade and the banks on the other side of it.

That is the concentration risk in the zinc trade. Not that the position is wrong, but that it is held disproportionately by one category of participant.

Copper: Funds Sit Still While the Physical Trade Moves

Copper barely moved. Fund net length fell 364.54 lots to +48,315.65, with longs cut 266.70 and shorts added 97.84.

That stillness is more interesting than it first appears, because the physical market was not quiet.

The largest move on the copper board came from commercial undertakings, who reduced their net short by 5,517.87 lots to −38,780.52, adding 6,186.42 lots of outright length. Investment firms and credit institutions went the other way, deepening their net short by 4,290.27 to −15,752.57.

Fund positioning in copper is almost entirely speculative — one lot long and 164 short classified as risk-reducing. Commercial undertakings hold the majority of their exposure as hedging: 83,978.67 lots long and 125,351.02 short in the risk-reducing category.

The shift is more consistent with changing physical or hedging requirements than with the outright directional speculation represented by the investment-fund category.

Lead: The Complex's Only Bear

Lead is the counterweight, and the most useful corrective to any claim that funds are simply long base metals.

Funds are net short 24,433.07 lots and became more so last week, by 723.35. They hold 23.63% of short open interest against 13.62% of the long side.

The mechanic is worth noting: both sides were reduced, with longs cut 1,427.57 and shorts cut 704.22. Funds are not aggressively adding to the bear case so much as withdrawing from lead altogether, with the long side withdrawing faster.

The contrast with zinc is instructive because the two metals are frequently co-products, mined from the same orebodies. Funds are positioned in opposite directions on metals that share a substantial part of their supply origin.

That is a meaningful statement about how the market reads the zinc story. It is being priced as a London availability problem specific to refined zinc — concentrate economics, Chinese smelter margins, warrant scarcity — rather than as a general base-metals supply thesis. If the trade were about mine supply broadly, lead would not look like this.

Nickel and Tin

Nickel added 1,697.88 lots to +16,132.57, with longs up 1,530.79 and shorts down 167.09. That is predominantly new buying, the same mechanic as zinc at smaller scale, and it corroborates that fresh capital entered base metals generally last week rather than zinc being an isolated case.

Tin is effectively dormant. Funds hold +2,569.00 lots across just 100 entities, and the reported positions are whole numbers — there is no delta-hedged option exposure at all. Given tin's five-tonne lot size and small market, funds are simply not engaged in the contract. That absence is worth recording precisely because tin's size means any future fund interest would move it disproportionately.

Bloodstone View

The aggregate figure — funds net long 252,582 lots across the complex — is close to useless as a description of what happened last week.

Aluminium and zinc added nearly identical net exposure. One did it by exhausting bearish capital, the other by attracting new capital. Those positions will not respond the same way to the same news.

Aluminium's advance has a finite fuel supply. With 41,337.68 lots of fund shorts remaining after an 11.2% weekly reduction, the covering that has driven four-fifths of recent buying has a visible end point. When it is complete, something else has to replace it or the move stalls. That does not make aluminium bearish. It makes the current rally structurally different from one built on conviction.

Zinc's advance has the opposite profile. Fresh length has been committed, which means more capital is exposed to disappointment but also that the buying reflects an actual view rather than a mechanical unwind. The physical evidence supported it through the reporting week: available inventory fell even as total stocks edged higher, backwardation widened sharply, and the price reached a four-year high. Prices have eased modestly since, which is the first test of whether the new length holds.

Copper shows the clearest divergence between financial and physical behaviour. A tightening driven by commercial requirements is harder to break than one driven by speculative length, because those buyers are not looking for an exit.

Lead is the discipline check. It confirms funds are discriminating between metals rather than expressing a directional view on the complex, and specifically that the zinc trade is being read as a refined-availability story rather than a mine-supply story.

For zinc, the test remains Chinese metal reaching London — and being warranted rather than cancelled.

For aluminium, the test is what replaces the short covering.

For copper, the test is whether commercial buying persists once immediate requirements are covered.

Outlook

Base case: Zinc stays supported while deliverable London stock remains scarce, though recently established length raises sensitivity to any acceleration in Chinese exports. Aluminium's advance loses momentum as the remaining short base is exhausted. Copper remains governed by physical rather than speculative flows.

Bull case: Chinese zinc smelters cut output under continued treatment-charge pressure, validating the new length. Aluminium attracts genuine long accumulation to replace covered shorts. Copper commercial buying persists as tariff-driven geographic distortion continues.

Bear case: Chinese refined zinc reaches LME warehouses in volume and is warranted rather than cancelled, forcing a crowded and recent long to unwind. Aluminium's short base empties with nothing behind it. Copper commercial demand is satisfied and the bid disappears.

Key Risks

• Zinc positioning is concentrated. Funds hold 30.68% of long open interest with the physical trade and banks on the other side. A crowded position in a thin deliverable market amplifies any reversal.
• Zinc length is recent. Net exposure rose 11.0% in a single week. Newly established positions are typically less resilient than long-held ones, and prices have already eased from the 26 August peak.
• Chinese zinc exports could accelerate. Still the clearest single threat to the London scarcity thesis. The relevant measure is metal warranted, not metal delivered.
• Aluminium's short base is finite. At 41,337.68 lots and falling 11.2% weekly, the mechanical support behind the advance has a measurable end point.
• Copper's commercial bid may be temporary. Physical buyers cover requirements and step away; the current tightening depends on that demand persisting.
• Correlated unwind across the complex. Funds hold 252,582 lots net long across six metals. Simultaneous reduction would amplify individual moves beyond what any single market's fundamentals imply.

Intelligence Monitoring Points

• Zinc fund longs: whether the position extends beyond 120,063.54 lots or begins trimming.
• Zinc long/short composition: whether further gains come from new buying or, as in aluminium, from short covering.
• Zinc cancelled warrants: 30,875 tonnes against total stocks near 99,125 tonnes. The ratio matters more than the headline inventory.
• Zinc deliverable stock: roughly 68,250 tonnes, under two days of global consumption.
• Zinc cash-3M spread: $231.75/t on 27 August. Whether it holds above $200/t indicates continuing nearby tightness.
• Aluminium fund shorts: currently 41,337.68 lots. The rate of decline determines how much covering support remains.
• Copper commercial undertakings: whether the net short keeps narrowing, indicating sustained physical demand.
• Lead fund positioning: whether the net short at −24,433.07 deepens or converges towards zinc.

FAQ

Q: What is the standout signal in this week's data? A: The divergence in mechanics between aluminium and zinc. Both added roughly 6,000 to 6,500 lots of net bullish exposure, but 79.9% of aluminium's came from short covering while zinc's came entirely from new buying.

Q: Why does that distinction matter? A: Short covering is self-limiting — once bearish positions are closed the buying stops. New length reflects active conviction and can continue building, but leaves more capital exposed if the thesis fails.

Q: How exposed is the zinc long? A: Funds hold 30.68% of zinc long open interest, nearly double their share in any other base metal, across 299 entities. Investment firms and commercial undertakings are both net short and added to those shorts last week.

Q: Why does copper's lack of movement matter? A: Because the physical market tightened at the same time. Funds sat still while commercial undertakings cut their net short by 5,518 lots — a shift more consistent with hedging and supply requirements than with directional speculation.

Q: Why include lead when it is a small market? A: Because it is the only net short and it is a zinc co-product. Funds positioned opposite on two metals from the same orebodies indicates the zinc trade is being read as a refined-availability story rather than a mine-supply story.

Q: What would most change this picture? A: A material acceleration in Chinese zinc exports being warranted into LME warehouses. It would undermine the deliverable scarcity and expose the freshly established fund long simultaneously.

Data: London Metal Exchange Commitments of Traders reports, positions as of 28 August 2026, published 2 September 2026. Positions are reported in lots. Total long and short open interest may not balance owing to trades suspended at clearing and differing modelling methodologies for delta hedge equivalent option positions; the LME reports the larger of the two as total open interest. Price, inventory and spread data as of 3 September 2026 where stated.

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.