A public dispute over how Coinbase handles customers who say they lost funds on the exchange has widened over the past week on X, drawing in one of the company’s own executives, a former employee, and Ari Paul, founder of crypto investment firm BlockTower Capital. Paul alleges Coinbase concealed repeated hacks. He has not made evidence public, and Unchained said it has not independently verified the claims. Coinbase denies hiding hacks.
The dispute began with a locked-account complaint
The thread started on Sept. 26, when a trader posting as kuno alleged that Coinbase had stolen $1.2 million from them a year earlier. The trader said they had opened more than 30 support tickets and gave the exchange 24 hours to resolve the issue before they would post a recording of a call with Coinbase staff and pursue legal action.
In an earlier post, kuno said the account had been locked without explanation.
Jordan Cobie Fish, who joined Coinbase through its $375 million acquisition of his fundraising platform Echo and took over the consumer Base app in July, replied that he could not find any account matching that description and asked kuno to send the account email.
Hours later, Fish wrote that there had been no response to any outreach by Coinbase to the user over the last 6+ months. He also said the dispute was being used to promote a token and that it looked like an “entirely fake/scam report/engagement farm.”
Ari Paul alleged concealed losses topping $1 billion
On Monday, Paul replied to Fish’s thread and said Coinbase had lost $25 million of his firm’s funds a couple of years ago and was “actually covering up massive and repeated hacks.”
He said his firm had traced the matter to at least a dozen other affected firms and to more than $1 billion in concealed losses.
The replies then broadened into complaints about Coinbase support more generally, with several users describing their own account problems. Unchained said it could not verify those claims.
- One X user wrote that “you have to tag Cobie to get anything done.”
- Another user, posting as Shitcoin CPA, claimed to have lost access to about $45,000 and wrote, “4 years later, I still don’t have my account back.”
- A third user said Coinbase froze their funds for several months over alleged suspicious activity and barely communicated during the review.
Paul said legal proceedings prevent him from releasing proof
In a follow-up post on Tuesday, Paul said he could not share proof because multiple legal processes were still unfolding. He also alleged that Coinbase had already tried to sue him into silence without success.
In another post, he apologized for moving slowly and wrote that he had never before taken on “such a politically powerful and aggressive legal bully.” He said he had fiduciary obligations to prioritize fund recovery while negotiating still appeared to offer a path to recover the money, and added that he no longer has those duties.
Coinbase responded Tuesday through its support account, saying it could not comment on specific clients.
The company wrote: “Coinbase is not hiding a series of hacks and we certainly didn’t lose $1B.”
Coinbase also said it advises customers on how to secure their API keys and that, like most companies offering API access, it does not retain the information necessary to transact on customer accounts.
Former Coinbase employee disputed Paul’s version
Justin Mart, who previously worked in corporate development and ventures at Coinbase, questioned Paul’s account on Wednesday. He said he would “bet a ton of money” that the accusations were “far far worse than reality.”
Mart said a more likely explanation was that BlockTower’s credentials were stolen, Lazarus Group used them to withdraw funds, and Coinbase processed those withdrawals. He added, “Obv I could be wrong.”
Paul replied that this was “Very wrong,” and said outside forensic firms and the Secret Service were involved. He also said his team traced the attack to a specific Coinbase codebase.
Paul said the attacker was likely the Lazarus Group, though “we’re not 100% sure.” He added that he would publish the full dossier with detailed proof if Coinbase agreed not to harass or sue him over it.
No stated link to Coinbase’s previously disclosed data breach
Unchained noted that in May 2025, Coinbase disclosed that criminals had bribed overseas customer service agents to steal customer data and demanded a $20 million ransom.
Paul has not said whether his allegations are connected to that breach.