Antofagasta stock rises 5.37% after guidance cut

Shares turn higher

Antofagasta plc (GB0000456144) stock climbed 5.37% to GBX 3,905 on August 21, 2026, with volume at 1.53 million shares. The move followed a week in which the shares also crossed above the 200-day moving average, a level flagged in recent market coverage.

Fresh commentary on August 13 and August 17 focused on the company's outlook after its half-year update, while price-target cuts from JPMorgan Chase and mixed analyst ratings kept the stock on watch. The same coverage also tied the move to stronger metal prices and weather disruption in northern Chile.

Half-year numbers matter

The July 15, 2026 half-year update was the key operating reference point in recent coverage, with copper production down 9.5% and full-year guidance still affirmed. That combination matters because it pairs lower output with unchanged guidance, a contrast investors have been trading around.

Analyst reaction stayed active into mid-August, with one note dated August 17, 2026 highlighting a lower GBX 4,300 target and another reiterating a sell stance. For a miner, that kind of split usually keeps the debate centered on volume recovery, copper prices, and cost control rather than valuation alone.

Weather and Chile

Recent reports on August 19 and August 20, 2026 linked Antofagasta to mudslides and flooding in northern Chile after extraordinary desert rains. That is relevant because the company's operations are concentrated in Chile, where weather can quickly affect logistics, mine access, and sentiment.

A separate report on July 24, 2026 said Antofagasta resumed Los Pelambres operations after severe weather disruption. The sequence from disruption to restart helps explain why traders remain sensitive to any new operational headlines from the region.

Los Pelambres

Los Pelambres is one of Antofagasta's best-known copper assets and remains a representative driver of group output. Copper production, guidance commentary, and weather resilience around that mine are still the cleanest way to read the stock's latest swings.

Closing level

Antofagasta shares closed at GBX 3,905 on August 21, 2026, after trading between GBX 3,776 and GBX 3,990 during the session. That leaves the stock more than 5 percent higher on the day, with the latest market update showing 1.53 million shares changing hands.

Fact box

Company: Antofagasta plc

ISIN: GB0000456144

Ticker: ANTO

Exchange: London Stock Exchange

Price (as of August 21, 2026): GBX 3,905

Market cap: not included in the available market snapshot

Sector / Industry: Basic Materials / Copper

Index membership: FTSE 100

Next earnings date: October 1, 2026