Trump said on Truth Social on Sunday that his January executive order on digital assets would create a stockpile of currencies including bitcoin, ether, XRP, solana and cardano. The names had not previously been announced.
More than an hour later, Trump added: "And, obviously, BTC and ETH, as other valuable Cryptocurrencies, will be at the heart of the Reserve."
Bitcoin, the world's largest cryptocurrency by market value, was up more than 10 per cent at $US92,459 ($A148,911) Sunday afternoon. Ether, the second-largest cryptocurrency, was up about 11 per cent at $US2,456 ($A3,956).
XRP is cryptocurrency company Ripple Labs' token. Ripple backed a so-called super PAC to influence congressional elections in November in favour of the crypto industry, Reuters reported.
"This move signals a shift toward active participation in the crypto economy by the US government," said Federico Brokate, head of US business at 21Shares, a digital assets investment management firm.
"It has the potential to accelerate institutional adoption, provide greater regulatory clarity, and strengthen the US's leadership in digital asset innovation."
James Butterfill, head of research at asset manager CoinShares, said he was surprised to see digital assets other than bitcoin included in the reserve.
"Unlike bitcoin ... these assets are more akin to tech investments," Butterfill said.
"The announcement suggests a more patriotic stance toward the broader crypto technology space, with little regard for the fundamental qualities of these assets."
Trump won support from the crypto industry in his 2024 election bid, and he has quickly moved to back their policy priorities. He is hosting the first White House Crypto Summit on Friday, and his family has also launched its own coins.
Under his Democratic predecessor, Joe Biden, regulators cracked down on the industry in a bid to protect Americans from fraud and money laundering.
Under Trump, the Securities and Exchange Commission has withdrawn investigations into several crypto companies and dropped a lawsuit against Coinbase, the largest crypto exchange in the US.
But in recent weeks cryptocurrency prices are down sharply, with some of the biggest digital currencies erasing nearly all of the gains made after Trump's election win triggered a wave of excitement across the industry.
Analysts say the market needs a reason to move higher, such as signs that the US Federal Reserve plans to cut interest rates or a clear pro-crypto regulatory framework from the Trump administration.
Reuters has reported that Geoff Kendrick, an analyst at Standard Chartered, is targeting bitcoin to hit $US500,000 ($A805,283), against a record high of $US109,071 ($A175,666), before Trump leaves office.
Regulatory filings in the US showed that while hedge funds remain the dominant crypto buyers, banks and sovereign wealth funds are buying too.
Quarterly filings showed that asset managers boosted allocations to US ETFs tied to the price of spot bitcoin in the fourth quarter of 2024.
Analysts and legal experts are divided on whether an act of Congress will be necessary to set up the reserve. Some have argued the reserve could be created via the US Treasury's Exchange Stabilization Fund, which can be used to purchase or sell foreign currencies.
Trump's crypto group had planned to look at potentially creating the stockpile with cryptocurrencies seized in law enforcement actions.
