It is not Donald Trump alone who is making the mining industry great again, although he has surely lent a hand.

His victory in the US Presidential election after pledging an infrastructure splurge pushed copper prices up 11% last week, the best performance in more than five years. Mining shares reached the highest price levels in almost two years.

The gains are a huge turnaround from the start of 2016. Commodity prices sank to a near seven-year low in January, with some of the largest miners fighting for survival under the weight of their debt.

“After a four- or five-year bear market, we’ve been clobbered over the head so many times we don’t believe in optimism,” said Jeremy Wrathall, Investec global natural resources chief. “That is changing – it’s definitely changing.”

Copper’s gain “appears premature”, driven by speculation by investors in China, and will fall back by the end of the year, Citigroup analysts, including David Wilson, said in a note. The euphoria after Trump’s win is “inexplicable” and is set to peter out, according to Commerzbank.

Copper’s lead in the industrial metals surge is partly down to its being the most traded and easiest to buy and sell, as well as its role as a proxy for speculation on faster economic growth.

While Trump has promised to build roads, bridges and airports, the US is a relatively small metals consumer. A 10% surge in its copper demand would be equivalent to just a 1.5% gain in consumption in China, the world’s number one user of commodities, UBS Group estimates.

Yet, with the Chinese economy also showing signs of recovery from its economic weakness last year, which drove commodity prices lower, mining companies may see Trump as the icing on an already expanding cake.

“Soon we may see China and the US engaging in national infrastructure build programmes at the same time,” said Tom Price, a Morgan Stanley commodities analyst in London. “They will be competing for the same commodities: steel raw materials, zinc and copper. We’ve never seen that before.”

Chinese policymakers have arrested weaker growth by spending on buildings, machinery and other fixed assets in recent months, and industrial output gains have stabilised above 6% from a year before, reports showed last week.

Also, miners have surprised equity investors with their ability to improve their financial condition by selling assets and cutting dividends and debt. The top four diversified miners have reduced borrowings in the past year by a combined $6.9-billion, or 8.5%, according to Investec.

That may reach $15.2-billion by year-end, with Glencore set to lower its debt by 38% and Anglo American by 26%, the bank says.

Shares in Glencore, the biggest commodity trader, added 17% last week and have more than tripled this year. BHP Billiton, the largest mining company, is up 74% this year and Anglo American’s share price has increased almost fourfold.

“Even the most hard-bitten people are turning round and saying, ‘We didn’t see this coming, but there is good reason for it happening’,” Wrathall said.