Copper prices are soaring, and ASX copper shares are riding the wave. Overnight, the price for the bronze-coloured metal hit US$10,000 per tonne as speculations on global tariffs begin to mount.

Rising copper prices are benefiting ASX-listed miners, with names like Capstone Copper (ASX: CSC) and Sandfire Resources Ltd (ASX: SFR) each seeing gains of more than 10% in the last week. Rio Tinto Ltd (ASX: RIO), which has a large portfolio of copper assets, is up more than 2%.

With copper hitting new highs, miners are benefitting from a boost. But what's driving this surge, and how long can it last? Let's take a look.

ASX copper shares benefit from price surge

Copper has been on a tear in recent weeks. On the London Metal Exchange, copper hit US$10,046.50 per tonne, its highest level since October last year. The optimism has flowed through to ASX copper shares.

But it's not all optimism. According to Trading Economics, the causes are twofold: global supplies and tariffs.

Meanwhile, inventories on both the London and Shanghai exchanges are declining. US President Donald Trump has recently threatened tariffs on copper imports, which could further strain the country's already limited smelting capacity. Currently, the US imports nearly half of its copper and relies on only two major smelters for domestic production.

As The Australian Financial Review reports today, traders are swiftly moving copper to the US to "take advantage of the price premium and skirt any potential tariffs on the metal".

The reporting notes that the US is expected to see up to 150,000 metric tonnes of copper arrive in the country, surpassing previous records.

This, combined with signs of recovering demand from China, the world's largest consumer of copper, has fuelled the price rise.

ASX copper shares have been major beneficiaries of this price surge.

Sandfire Resources has been one of the standout performers in the copper space. The company booked a sharp increase in copper equivalent production in the first half of FY25, and its share price is up nearly 32% in the past year.

As The Bull reported last month, Fairmont Equities is bullish in the stock, expecting it to "trend higher" with the strength in copper prices.

Capstone Copper is another ASX-listed stock benefiting from the copper rally. The company has capitalised on higher copper prices.

As my colleague Bernd reported today, the copper player successfully completed a bond issue of US$600 million to finance its operations and pay down some existing debt.

The ASX copper share has surged by 12% in the past week after a six-month low of $8.11 apiece in early March.

Capstone was last at $9.79.

Foolish takeaway

The rise in copper prices has been great news for ASX copper shares. These companies are benefiting from a surge in demand for the metal, particularly in the wake of potential tariffs and tightening global supply.

Time will tell what happens from here, or if there even will be tariffs imposed. For the time being, the market is bullish on these stocks.