• Mark Cuban criticized Bluesky for becoming an echo chamber, warning it was driving some users away.
• Engagement on Bluesky has plunged since February, with far fewer daily unique users.
• Cuban questioned BlueSky's future, citing vanishing nuance and an absence of some topics.

Mark Cuban is sounding the alarm on Bluesky's declining engagement — and he's not pulling his punches.

In a series of Bluesky posts, the billionaire investor and entrepreneur criticized the platform for fostering an echo chamber that he said was driving users away and inadvertently boosting traffic back to Elon Musk's X.

"The lack of diversity of thought here is really hurting usage," Cuban wrote, linking to a Washington Post opinion piece headlined "BlueSky's decline stems from never hearing from the other side."

Once known for "great give-and-take discussions on politics and news," Cuban said Bluesky had become a monoculture where dissent was unwelcome and nuance was vanishing.

"Engagement went from great convos on many topics, to 'agree with me or you are a Nazi fascist,'" he posted.

A graph of Bluesky's unique daily posters supports his concern.

On February 28, Bluesky had more than 1 million unique users daily. Since then, engagement has plummeted, with June 7 and 8 hovering well below that peak at about 670,000 daily posters.

The Musk factor

BlueSky's rise accelerated following the election of President Donald Trump, whom CEO Musk backed financially, and after X introduced new terms of service.

Many X users migrated to Bluesky, with some 2.5 million joining in one week in November.

Some were seeking a friendlier, more open platform with less hate speech and misinformation, and more control over what content is shown in their feeds.

A startup, BlueArk, even sprang up to help users migrate their X/Twitter histories to Bluesky, porting over millions of posts and creating the illusion of continuity on a new platform.

At the time, Cuban told Business Insider he preferred Bluesky over alternatives due to its variety of content and growing engagement.

Now, some of the earliest and most visible converts, including Cuban, are questioning whether the migration created a new community, or just repackaged the same silos.

"Why would anyone stop using Twitter if the only topic that is acceptable to you is news and politics?" he asked.

Cuban also criticized the platform's culture, saying: "The replies on here may not be as racist as Twitter, but they damn sure are hateful."

Posts about AI, business, or healthcare — traditionally strong areas for Cuban — often gain little traction or were met with outright hostility, he added.

Cuban also questioned Bluesky's business model: "How does everyone suggest BlueSky survive as a business? Or do you not care?"

• The OECD cut its forecast for US economic growth in 2025 from 2.8% to 1.6%.
• It cited President Donald Trump's tariffs, which had pushed the US import rate to the highest level since 1938.
• Global growth is also set to slow as trade tensions disrupt investment and inflation rises, the OECD said.

The US and global economy are losing steam, and a key forecaster said President Donald Trump's trade tariffs were part of the reason.

In its latest Economic Outlook, released on Tuesday, the Paris-based Organization for Economic Co-operation and Development cut its forecast for US economic growth in 2025, pointing to the fallout from the administration's trade policies. The 2.8% rate it predicted in March has now been reduced to 1.6%.

The OECD warned that these tariffs, which have pushed the effective US import rate to 15.4% — the highest since 1938 — were not only affecting US growth but reverberating across the global economy too.

Global growth was now projected to slow to 2.9% in both 2025 and 2026, down from 3.3% in 2024.

The OECD said the slowdown in growth was concentrated in the US, Canada, Mexico, and China. Growth in China, the world's second-largest economy, was expected to fall to 4.7% in 2025, down from 5% last year, and come in at 4.3% in 2026.

As of May 27, a blanket 10% tariff applies to all goods imported into the US, with some limited exemptions.

Stoking inflation

A 50% tariff on imports from the European Union were paused until July 7 amid "fast-tracked" negotiations, while steep levies on imports from China have also been put on hold.

The OECD said these policies were eroding investment, disrupting supply chains, and stoking inflation — especially in the US, where price growth is now projected to approach 4% by the end of the year.

OECD secretary-general Mathias Cormann said governments needed to work to keep markets open and preserve the "economic benefits of rules-based global trade for competition, innovation, productivity, efficiency and ultimately growth."

Chief economist Álvaro Pereira added: "Lower growth and less trade will hit incomes and slow job growth."

The organization urged governments to de-escalate tensions and roll back tariffs to avoid further damage to the global economy.

In a Monday note, Deutsche Bank economists said there were global signs of a "turbulent but sustained path toward trade de-escalation. The fallout from the US 'Liberation Day' policies — from falling approval ratings to a sell-off in US government bonds — forced a rethink in Washington. While recent court rulings could pave the way for an even more benign trade regime, they also prolong uncertainty."

The bank also expected US GDP to grow by 1.6% this year and by 1.7% in 2026 on an annual average basis.