Monday’s trading action was bizarre in many ways.
But one specific mystery — about a misleading headline that sent stocks ping-ponging all over the place — highlights just how fragmented and expensive access to breaking financial news can be, even at times when it really matters to retail investors.
The US stock market did indeed go bananas this morning, thanks to a headline that falsely* claimed White House adviser Kevin Hassett had said President Donald Trump was considering a 90-day pause in tariffs.
CNBC anchors read out the headline on air, as they tried to explain why markets had started to soar. In all, the S&P 500 rallied nearly 6 per cent from where it had been trading right before the mystery headline.
The White House said within the hour that no one knew about this supposed plan, a rare chance to properly use the term “Fake News”. Stocks sold off by the same amount they’d rallied, and then see-sawed around for a while. By mid-afternoon they were basically flat for the day.

So where exactly did the headline come from? That’s a tougher question to answer than you’d think.
The obvious point of contagion was the Walter Bloomberg account, using the X handle @DeItaone (with a capital I instead of an “L”) which says it’s based in Switzerland.
This is not a guy named Walter Bloomberg, nor does he write for Bloomberg. The account’s entire deal is just reposting financial newswire headlines.
Here’s the post via a screengrab (since the account has since deleted the post). As you can see, it came at 10:13am, and really made the rounds within the next 30 minutes or so, thanks to the account’s ~848,000 followers:

So did someone posting as “Walter Bloomberg” make up a headline to save the market? To cash out? Or just to introduce some chaos into the day? If so, it’d be a little strange for the account to keep posting! Mostly because that type of thing seems . . . actionable. It also seems like it’d be a bad idea for the account to attract this type of scrutiny.
As we said, it basically just copies financial breaking-news headlines from newswires, and those wires often come with an extremely pricey subscription. If Hassett had done an exclusive interview about major US policy decisions — he did not, probably* — only a major financial news service would’ve been able get that exclusive access.
The newswires don’t just offer one uniform news feed, either. While we aren’t 100% up to speed on the latest business models, some newswires have been known to deliver news feeds to different subscribers at different speeds. This is reasonable, to an extent, because not all professional subscribers can use the same level of access.
So it does seem possible that some experimental headline-writing product (or a budget subscription) published a bad headline that was then picked up by the Walter Bloomberg account.
There’s also one less-than-obvious analogue with reality that could’ve been misinterpreted by an overzealous headline writer or (ahem) LLM. In a Fox & Friends interview, National Economic Council director Kevin Hassett stalled by saying “yep” before saying “the President is going to decide what the President is going to decide.”
This was obviously not confirmation, especially because he then argued that observers are overreacting to the tariffs news. Another problem with that explanation is that the interview happened nearly two hours before @DeItaone published the headline.
Whoever’s running the account isn’t helping to solve the mystery, either.
When asked by followers, it cited both Reuters and CNBC as the sources of the headline. Remember, though, the CNBC anchors seemed to be reading his post! One of his screengrabbed sources shows a Reuters newswire headline. But that was from 10:23am, and cites CNBC:
— *Walter Bloomberg (@DeItaone) April 7, 2025
Now, it’s not great if CNBC flashed a headline because one of their anchors read a social-media post that turned out to be nonsense. In their defence, however, markets had already started to take off before they read it!
So it’s starting to look like the main thing we’ve learned today is the influence of the @DeItaone account and its ~849,000 followers. Are that many traders really following an aggregator to save money? Or are markets just so hyperresponsive that even an X Anon can cause a 6-per-cent swing?
Things get even weirder.
An account called Hammer Capital posted the same headline at 10:11am. That’s before the post from Walter Bloomberg, or CNBC, or any other sources we’ve found. Hammer Capital’s been on X since March 2021, and we’re including a screengrab of his post below, in case it’s deleted:

We’ve contacted both him and the “Walter Bloomberg” account for comment. That was through DMs, though, so it’s unclear whether we’ll have much success.
We’ve also contacted Reuters. They haven’t responded, but did publish an “ADVISORY-Story withdrawn on Hassett’s comments on tariff pause”. In that retraction, Reuters said it originally published the story because of CNBC. We’ve contacted CNBC for comment as well, and will update with anything we hear.
Anyway, the market has been zigzagging all over the place since this morning. That’s presumably because some traders think the US President can be swayed by market reactions to fake news.
Or, as the @Quantian account puts it:
So we bounced 8% on a fake headline, sold off when people realized it was fake, and then bounced again when it occurred to people that if we bounced that much on a fake headline imagine how much we’d bounce on a hypothetical real one.
*The original headline’s accuracy could, of course, change entirely at any moment, at the whims of one man. How fun! Also an earlier version of this headline said Twitter instead of X. Whoops.
https://www.ft.com/content/901a7a75-2f68-4abd-9ec2-246a3d9b3105