A slide in copper dragged London's Mining heavyweights sharply lower on Tuesday, and the sector's losses shaped the FTSE 100's worst session in a month.

Copper's slide to a seven-week low on Tuesday 3 November 2026 rippled straight through London's stock market. The FTSE 350 basic resources index fell 2.6%, and the selling in mining shares did much to set the direction for the FTSE 100, which closed down 122.90 points, or 1.14%, at 10,638.43.

Mining stocks carry substantial weight in the Blue-Chip index, so when they fall together the effect on the headline figure can be pronounced. Tuesday's session, which Reuters described as the FTSE 100's steepest one-day fall in a month and which ended a four-day winning streak, showed that dynamic clearly.

Copper leads the way down

The trigger was the metal itself. Alliance News reported that copper fell 2.5% on the day, while midday reports from Reuters, carried by Share Talk, said copper had reached seven-week lows. That pushed industrial metal miners to their lowest level in almost four months.

Copper is widely used in construction, power networks and manufacturing, so its price is often treated as a barometer of global economic activity. When it falls, investors may read it as a sign of softer Demand expectations, and the shares of companies that mine it tend to react quickly because their profits are closely linked to the price they receive.

The precious metals end of the sector was hit as well. Precious metal miners fell about 2.7% to a three-month low by midday, so the weakness was not confined to producers of industrial metals. When both halves of the sector fall at once, it can suggest a general retreat from commodity-linked risk rather than a problem specific to one metal or one company, and that broad-based quality helps explain the size of the hit to the index.

Several of the FTSE 100's best-known resource names were among Tuesday's notable decliners:

Antofagasta (LSE:ANTO)fell 3.5% by the close, according to Reuters, making it one of the steepest fallers among the blue-chip miners as the metals sell-off gathered pace.

Glencore (LSE:GLEN)dropped 2.8% at the close, also caught up in the metals sell-off.

Anglo American (LSE:AAL)was down about 2.8% at midday, moving lower alongside its mining peers.

Endeavour Mining (LSE:EDV)declined with precious metal miners, although no specific percentage move was reported.

Because these companies are large, their combined losses subtracted a meaningful number of points from the FTSE 100. The index is weighted by market capitalisation, which means a broad slide across several big constituents in one sector can move the overall benchmark more than scattered falls elsewhere.

A broader risk-off mood

Mining was not the only source of weakness, and the sector's slide happened against a cautious backdrop. The FTSE 350 banks index fell 1.6% ahead of the Bank of England's decision on Thursday 5 November, with HSBC (LSE:HSBA) down 2.0% and acting as the largest approximate drag on the FTSE 100 in points terms. Associated British Foods (LSE:ABF) was among the index's fallers after forecasting lower annual profit, and Coca-Cola Europacific Partners (LSE:CCEP) fell 2.1% after flagging cost pressures.

Energy markets added to the uncertainty. Crude slid about 2% on Tuesday in volatile trade, after a roughly 7% fall on Monday, as investors weighed talks aimed at ending the wars in Ukraine and Iran. Brent had settled Monday at $104.77. Elevated oil prices have stoked Inflation fears, and Reuters noted that many central banks have raised rates. Higher borrowing costs can weigh on expectations for economic growth, which in turn can feed into views on demand for industrial metals.

The US midterm elections, held on Tuesday with all 435 House seats and 35 Senate seats contested, may also have encouraged some caution. Reuters said a Democratic showing was considered priced in, and results were not known during the London session.

Why the miners matter so much

The scale of Tuesday's resources sell-off is a reminder of how much the FTSE 100's daily performance can depend on a handful of sectors. When Commodity prices move sharply, the index often moves with them, even if the UK economy itself has not changed overnight. That is one reason the FTSE 100 is sometimes described as a global index that happens to be listed in London.

The contrast with the FTSE 250 underlines the point. The mid-cap index, which has much less exposure to large mining groups, fell only 0.5% to 24,674.91 on the same day. Within the FTSE 100, Hiscox (LSE:HSX), an insurer with no direct commodity exposure, rose 2.9% after reporting a 9.5% rise in nine-month premiums, showing that stock-specific news could still lift individual names.

For investors following the resources sector, the key question is whether copper's slide reflects a short-lived wobble or a more sustained shift in demand expectations. That is unlikely to be settled by a single session, and the sector's direction may depend on wider signals about global growth, interest rates and energy costs in the weeks ahead.

Key dates to watch

Thursday 5 November:Bank of England MPC decision, with a 25bp rise to 4% widely expected; Metlen Energy & Metals also reports third-quarter figures.

Friday 6 November:US October jobs report, a key read on the world's largest economy.

Thursday 12 November:ONS first quarterly GDP estimate for July to September 2026 (7:00am).

Wednesday 2 December:FTSE Russell December review announcement after the UK close.

The bottom line

Tuesday's 2.6% drop in the FTSE 350 basic resources index set the tone for a difficult session in the FTSE 100. Copper's fall to a seven-week low hit Antofagasta, Glencore and Anglo American, while precious metal miners such as Endeavour also slipped. Combined with bank weakness and cautious company updates, the miners' losses helped drive the blue-chip index to its steepest fall in a month. How metals markets respond to this week's Central Bank decision and US data may shape whether the sector steadies or remains under pressure.