Copper prices hit a record high of more than $14,000 a metric ton on Thursday, as speculators extended their buying spree, encouraged by expectations of strong demand and supported by a weak dollar and geopolitical concerns.

Copper stocks and ETFs jumped. Southern Copper, United States Copper Index Fund, and Ero Copper rose 9%; Global X Copper Miners ETF rose 8%; Freeport-McMoRan and iShares Copper and Metals Mining ETF rose 6%; BHP Billiton and Rio Tinto rose 4%.

They ignored warnings by some analysts that high prices would chill physical demand by industrial consumers and was not being supported by current supply/demand fundamentals.

Benchmark three-month copper on the London Metal Exchange jumped 9% to an all-time high of $14,268 a metric ton, paring gains to $14, 147 by 1315 GMT.

In LME official open-outcry trading, copper gained 6.6% to $13,950 a ton.

"Copper posted its biggest one-day gain in years... driven by intense speculative trading by bulls in China," Neil Welsh at Britannia Global Markets said in a note.

"Investors are piling into base metals on expectations for stronger U.S. growth and more global spending on data centres, robotics and power infrastructure."

Copper, used in power and construction, is a key metal needed for the energy transition, but global exchange-monitored inventories are at high levels, especially in the U.S.

The most-active copper contract on the Shanghai Futures Exchange closed daytime trading 6.7% higher at 109,110 yuan ($15,708.77) a ton, after setting a record of 110,970 yuan.