WASHINGTON — Donald Trump is embarking on what could be the biggest giveaway to some of the country’s richest since the nation’s “robber baron” days by having the federal government acquire and hold cryptocurrencies, which critics, including many economists, describe as a “greater fool” scam.

Trump announced the creation of a “crypto strategic reserve” on Sunday while playing golf at one of his courses in Florida. “A US Crypto Reserve will elevate this critical industry after years of corrupt attacks by the Biden Administration, which is why my Executive Order on Digital Assets directed the Presidential Working Group to move forward on a Crypto Strategic Reserve that includes XRP, SOL, and ADA. I will make sure the US is the Crypto Capital of the World,” he wrote on social media.

About two hours later, still at his golf course in West Palm Beach, Trump added two other “tokens” in a second post: “And, obviously, BTC and ETH, as other valuable Cryptocurrencies, will be the heart of the Reserve. I also love Bitcoin and Ethereum!”

The declarations sent the price of the named cryptocurrencies soaring —resulting in an increase of hundreds of billions of dollars in total value for Bitcoin alone.

Trump White House officials would not say how much Trump intended to place in this strategic reserve and where that money would come from. White House spokesperson Victoria LaCivita pointed to a Sunday social media post from Trump’s “crypto czar” David Sacks, who promised more details at the coming White House “crypto summit” on Friday.

Sacks is a multibillionaire venture capitalist and cryptocurrency proponent. He has said he has divested all his crypto holdings to take the White House role, but his company still reportedly has stakes in all five of the tokens Trump named.

If the crypto reserve’s funding comes from taxpayers and is in the billions range — anything less than that would be a rounding error, given the size of the US economy ― it would mean a massive boost to existing owners of the virtual money, economists said.

“It’s great to have the government buy stuff you own, yes,” said Douglas Holtz-Eakin, a conservative economist who served as former Senator John McCain’s top economic adviser during his 2008 presidential run. “If he invests in my morning emails, I think the country would be better off.”

Holtz-Eakin was among economists from across the political spectrum who said they could not understand why the United States should even want a “reserve” of something like cryptocurrency.

Stephanie Kelton, a professor at Stony Brook University and a proponent of modern monetary theory, quoted Republican writer David Frum: “‘They’re libertarians who want a US Treasury bailout for their fake money.’ It makes no sense otherwise.”

Not long ago, Trump himself was a vocal critic of the relatively new industry, which has exploded in recent years with the sale of digital artwork and “meme” coins, with buyers hoping they increase in value.

“Bitcoin, it just seems like a scam,” Trump said in June 2021. “I don’t like it because it’s another currency competing against the dollar.”

That view, though, changed after Trump met with crypto investors and started receiving large contributions from them to his super PACs as he ran to regain the White House last year. He spoke at the Bitcoin Conference last year and promised to make the United States the “crypto capital” of the world.

In all, the cryptocurrency industry poured $119 million into Trump’s election, with millions more for his inauguration.

Trump and his family joined in to profit off it all personally. He and his sons launched the crypto brokerage World Liberty Financial last September, and just days before taking office, Trump issued a digital “coin” from which he and his partners have already earned nearly $100 million in fees.

If the “crypto reserve” ends up with tens or hundreds of billions of dollars, the financial benefit to some of the country’s wealthiest would be unmatched in US history in a century and a half, since the time the government gave land to the robber barons for the purpose of building railways and drilling for oil in the 1800s.

But at least that giveaway provided ordinary citizens with cheaper, faster transcontinental transportation and cleaner, more efficient fuel than wood and coal. It’s unclear how typical Americans might benefit from a digital assets reserve unless they themselves have personally bought some of the coins already.

Unlike most investment assets, cryptocurrencies are based on nothing tangible. Stocks make shareholders part owners of a company and often provide periodic dividends. Bonds are loans to a company or a government and generate interest payments. A home typically appreciates in value while also providing the owner a place to live.

Cryptocurrencies do none of those things and instead merely record someone as the owner of a virtual value that exists nowhere but in an electronic ledger. While the privacy created by the ability to buy crypto anonymously has been useful for money launderers and other criminals, at least so far, there has been near zero utility for normal wage earners, consumers and investors.

“A bitcoin reserve is a little like using US tax dollars to buy stock in Twitter because Donald Trump and Elon Musk are buds,” said Massachusetts Democratic Sen. Elizabeth Warren on Monday. “It works great for the people who already own the Twitter stock or the five Bitcoins, but it really sucks for everyone else.”

Crypto’s value is based solely on what buyers are willing to pay for it at any given moment, which is why many, if not most, mainstream economists describe it as a “greater fool” scam that depends on investors hoping that others are willing to pay even more for their “asset” than they did.

“Crypto is a technology looking for a legitimate use case. That may change, but crypto is currently mostly a vehicle for speculation,” said Mark Zandi, chief economist with Moody’s Analytics. “The only clear beneficiary would be crypto owners, certainly not US taxpayers.”

“It’s a speculative asset. Good for people who like betting on ‘number go up’ – or ‘down.’ Good for people who want to transact in the shadows ― drugs, arms, human trafficking, et cetera,” Kelton said, adding that proponents who call it a good “store of value” are simply wrong. “It’s a sentiment-driven speculative asset. It is ‘worth’ whatever market sentiment decides it is ‘worth’ on any given day. It lost 17.5% of its value last month. Not exactly what I would call a good ‘store of value.’” 

HuffPost’s Igor Bobic contributed to this report.