Adam Back disputes Mark Cuban over bitcoin sale

Blockstream CEO Adam Back challenged Mark Cuban’s public criticism of bitcoin after the billionaire disclosed he had sold most of his holdings. In a social post dated May 23, 2026, Back published performance figures he said contradicted Cuban’s view.

Back’s post showed that since tensions in the Middle East escalated, bitcoin climbed about 25–30% from a low near $60,000. Over the same window the S&P 500 rose roughly 11%, the Dow Jones Industrial Average increased about 5%, and gold fell close to 14%. Back wrote: “Bitcoin is up 25-30% from the ~$60k bottom … vs S&P500 up 11%, DJIA up 5%. and gold fell -14%. so i don’t know what @mcuban is trying to say .. doesn’t line up with data unless he sold the bottom.”

Cuban had written that he sold most of his bitcoin after a period when the token fell more than 40% while gold climbed to about $5,000. He described bitcoin as having failed to act as an inflation hedge and a geopolitical safe haven during that stretch, and indicated he was more optimistic about Ethereum going forward.

Back attributed the earlier bitcoin drop to the “10/10 event” and to the cyclicality that follows bitcoin halving events, and he treated those factors as separate from gold’s gains. In the same post he added, “You don’t get the outlier Sharpe ratio over longer durations, without volatility. So it comes with the territory.”

Traders and followers of long-term bitcoin models argued Cuban misunderstood the asset’s behavior, pointing to multi-year risk-adjusted returns that in past cycles have outpaced equities, gold and real estate while showing large swings over short periods.

Market participants said whether Cuban’s sale was a timing error or a reassessment of bitcoin’s characteristics will become clearer only over the next market cycle, as more data accumulates on bitcoin’s performance during inflationary pressure and geopolitical stress.