Table of Contents
ToggleIn brief
- Coinbase CEO Brian Armstrong rattled off a handful of words after seeing prediction market on his firm’s earnings call.
- The stunt, which Armstrong called spontaneous, has drawn mixed reviews from industry observers.
- Some users praised Armstrong’s antics, while others likened it to market manipulation.
Coinbase CEO Brian Armstrong helped some prediction market users get paid during his firm’s Q3 earnings call on Thursday, rattling off a handful of words to the delight of users who had wagered on him using them.
“I was a little distracted because I was tracking the prediction market about what Coinbase will say on their next earnings call,” he said. “I just want to add, here the words ‘Bitcoin,’ ‘Ethereum,’ ‘blockchain,’ ‘staking,’ and ‘Web3’ to make sure we get those in before the end of the call.”
Armstrong was tracking a mentions market, a market type which asks users what words will be said during a specific event. Such markets were available on prediction markets Kalshi and Polymarket, asking users to place their guess as to what Coinbase would say on its earnings call.
Armstrong’s last-minute inclusions sent odds for words like “Web3” and “Ethereum” almost straight up to 100%, ultimately paying out predictors that expected a Coinbase representative to utter them during the quarter-capping call.
The event was allegedly derived from a member sharing a link to one of the markets in a chat with the Coinbase executive, he later posted on X. Dubbed as “fun” by Armstrong, the stunt drew mixed reviews from industry observers.
While some called the move “amazing” or referred to the Coinbase co-founder as a “chad,” others pointed to the act as failure of prediction markets—and alleged that it was a “blatant example of insider trading.”
“I’m tired of dumping on Clownbase, but you need your head examined if you think it’s cute or clever or savvy that the CEO of the biggest company in this industry openly manipulated a market,” posted Arca CIO Jeff Dorman on X.
“Brian’s closing remarks were made in a lighthearted, offhand way, referencing online discussion around the earnings call,” a Coinbase spokesperson told Decrypt. “Coinbase has robust policies and internal controls that prohibit employees, including executives, from participating in prediction markets or any related activity involving the company. Coinbase is committed to the highest standards of integrity, transparency, and compliance.”
Ethereum founder Vitalik Buterin came to Armstrong’s defense in a similar manner on X, telling followers he thinks Armstrong thought he was having fun, and the ETH icon “wants to be part of a fun-loving society.”
I think Brian thought he was having fun, and I want to be part of a fun-loving society 😛
— vitalik.eth (@VitalikButerin) October 31, 2025
Armstrong’s last-second mentions did not contribute to any major financial successes, as markets on Polymarket and Kalshi had low liquidity and total volumes of $4,000 and $80,000, respectively.
For example, “Web3” and “staking,” both words that he scrambled in at the last moment, managed under $450 in combined volume on Polymarket.
“Lmfao, Brian you’re a legend, but next time you gotta balance it out and do the ‘no bros’ a solid,” posted a Kalshi user after the stunt.
Both Polymarket and Kalshi have benefited from the rush of activity and hype surrounding prediction markets of late. The companies have completed additional raises in the last month, valuing their respective businesses in the billions.
Coinbase beat its Q3 earnings estimate on increased revenues. COIN shares finished the day trading up nearly 5% to $343.78.
Editor’s note: This story was updated after publication with a comment from Coinbase.
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