Copper headed for its lowest close since March as stockpiles surged by the most in four years, underscoring weak demand in Asia.

The 42,175-ton inflow took inventories on the London Metal Exchange to the highest level since 2019, with the material flooding into sheds in South Korea and Taiwan. That’s a sign of tepid consumption in China, where the LME has no warehouses.

The country, typically a massive net importer, has exported record volumes of the metal in recent months. That has upended global trade flows and unnerved bulls who have been bailing on bets that demand will improve.

Investors are often cautious about reading too much into individual stock movements on the LME as deliveries and withdrawals can sometimes be driven by commercial motives disconnected from underlying supply and demand. But with stockpiles rising steadily on both the LME and in China, they have increasingly been viewed as a worrying barometer for the health of demand in the world’s top commodities consumer.

Industrial metals have had a messy week so far, with aluminum and zinc also retreating as a rush from risk assets wiped billions off global markets. Heightened fears about a potential hard landing for the US economy added to concerns over tepid activity in China’s manufacturing sector.

Copper fell 1.7% to $8,777.50 a ton on the LME as of 3 p.m. local time, curbing this year’s gain to less than 3%. Aluminum dropped 1.7% and zinc lost 1.3%.

Written by: Bloomberg News — With assistance from Sana Pashankar @Bloomberg