Billionaire Ken Griffin has sided with Elon Musk in his attack on Donald Trump‘s ‘Big Beautiful Bill’.

The Citadel CEO warned the act will ‘add several trillion dollars’ to the national debt, which will soon surpass $37trillion.

Unlike Musk, who called the bill a ‘disgusting abomination,’ Griffin criticized the legislation in more conciliatory terms.

‘The bill will unquestionably add several trillion dollars,’ Griffin said Thursday at the 2025 Forbes Iconoclast Summit in New York City.

‘The challenge with the legislation is there’s not enough tough decisions… around how we’re going to put our fiscal house in order.’

Griffin made his concerns known about runaway government spending after the Congressional Budget Office estimated the GOP budget bill would add $2.4 trillion to the deficit over the next 10 years.

Much of this comes down to the bill’s extension of the 2017 Trump tax cuts, which will decrease the revenue coming into the government.

Griffin, who voted for Trump in the 2024 election, did not say he disagreed with the extension of the prior tax cuts. But he did take issue with even more tax relief for businesses.

‘The continued reduction in tax rates for small and medium enterprise businesses; I’m not sure what we’re going to achieve with that,’ said Griffin, who is estimated to have a net worth of $44.5 billion.

Griffin cast the bill, which is still winding its way through the Senate, as poorly thought out and dangerous to the nation’s finances.

‘You cannot run deficits of 6 or 7 percent [higher than GDP] at full employment after years of growth. That’s just fiscally irresponsible,’ said Griffin, who is worth $44.5 billion. 

‘There are a lot of question marks in the bill as to why we’re continuing to increase our tax cuts when we have a fiscal deficit of this magnitude,’ he added.

White House spokesperson Kush Desai didn’t directly address Griffin’s criticisms, instead contradicting the CBO by saying the big beautiful bill will ‘deliver the largest deficit reduction in decades.’

‘Despite endless doomsday predictions about President Trump’s tariffs, economic indicators have continued to improve – including expectation-beating inflation reports, strong real income growth, robust jobs reports, and rising consumer confidence,’ Desai told DailyMail.com.

‘The White House remains focused on passing the The One, Big, Beautiful Bill to deliver the largest deficit reduction in decades and pro-growth policies like historic tax cuts and full equipment expensing to further turbocharge America’s economic resurgence,’ Desai added.

Griffin also warned that if America’s leaders fail to rein in spending, they risk a total collapse of US bond markets.

Last week, JPMorgan Chase CEO Jamie Dimon sounded a similar alarm, predicting that at some point, investors will lose confidence in the US government’s ability to service its debt.

‘US default prices are probably the same as Italy or Greece,’ Griffin said in reference to credit default swap markets where investors can bet on countries failing to meet their debt obligations.

The consequences of a default – i.e. the country running out of money to pay its bills – would be ‘catastrophic’ for the US and the global economy, former Treasury Secretary Janet Yellen has said.

The stock market would almost certainly crash in such a scenario, with investors around the world coming to the understanding that the US – thought to be the most stable government in the world – could not fulfill its financial obligations for the first time in its nearly 250 years of existence.

Back in April, when Trump unveiled and quickly paused his wide scale Liberation Day tariffs, multiple reports suggested that his U-turn was prompted by the major sell off in US bonds.

Trump appeared to acknowledge this market turmoil at the time, saying: ‘People were getting a little bit yippy, a little bit out of line.’ 

Griffin didn’t limit his criticisms of the administration to uncertainty on US debt or the big beautiful bill, which Trump wants passed by the Fourth of July.

He also slammed the president for his ongoing trade policy, largely governed by historically-high tariffs.

He said the tariffs have ‘really taken their toll already on our economy’ and have called ‘into question American exceptionalism.’

His firm Citadel has already cut its estimate for US economic growth by about half since Trump took office in January.

As a parting shot at the president, Griffin decried Trump’s decision to tear into Walmart CEO Doug McMillon for warning customers that the big-box retailer may have to increase prices thanks to tariffs.

‘Walmart should STOP trying to blame Tariffs as the reason for raising prices throughout the chain. Walmart made BILLIONS OF DOLLARS last year, far more than expected. Between Walmart and China they should, as is said, ‘EAT THE TARIFFS,’ and not charge valued customers ANYTHING, Trump posted to Truth Social in May.

This didn’t sit well with Griffin, who argued that McMillon was simply showing candor in the face of dynamic tariff policies.

‘We should not criticize CEOs for being honest, right? And that’s all the CEO of Walmart was doing,’ Griffin said. ‘Shame on the administration.’