Brian Armstrong concluded Coinbase’s Q3 earnings call on October 30th with a statement announcing the immediate resolution of the live prediction market contracts on Polymarket and Kalshi.
The episode sparked debate over whether the industry’s most visible CEO was just mocking a niche gambling establishment or whether he had crossed a line where regulated financial executives should not go near.
Armstrong said in the final seconds of the conference call.
“I got a little distracted because I was following the prediction market of what Coinbase would say on their next earnings call. And to make sure I understand them before the call ends, I would like to add the words Bitcoin, Ethereum, Blockchain, Staking, and Web3 here.”
Although the confession was casual and almost disposable, by the time the verdict was over, roughly $90,000 in stakes between Carsi and Polimarket had flipped from uncertain to settled.
The response split along predictable fault lines. Prediction market builders and crypto-native traders laughed it off as harmless trolling.
Meanwhile, market participants saw something else. The CEOs of publicly traded, regulated financial companies are openly manipulating markets, even in small markets, giving ammunition to all the skeptics who say the industry is too immature for institutional investors.
Market situation
Calci, a CFTC-regulated designated contract marketplace, has listed an event contract titled “What will Coinbase say on its next earnings call?” Displays a binary yes or no result for a given word.
Polymarket ran a similar mention bet with the rule that if someone spoke during the call, the contract resolved to “yes.”
About $84,000 was bet on Mr. Carsi, but the Polymarket vote ended with a volume of about $4,000.
The deal was settled shortly after Mr. Armstrong’s closing remarks, with payments made to holders who had bet “yes” on Mr. Armstrong’s words.
Mention Marketplace pays when a specified term appears in a defined event window, regardless of context.
Mr. Armstrong’s admission that he was “tracking a prediction market” revealed what was already structurally effective: bettors could easily force a settlement with their words.
| platform | market labels | Total bet amount | Resolution time | payment memo |
|---|---|---|---|---|
| Karushi | “What will Coinbase say on its next earnings call?” | ≈$80,000-$84,000 | Immediately after Mr. Armstrong’s approval on October 30, 2025 | The deal was resolved with a “yes” to the words listed after the CEO’s final decision line. |
| Polymarket | “Revenue Mention: Coinbase (October 29/30, 2025)” | ≈$3,900-$4,000 | Immediately after Mr. Armstrong’s approval on October 30, 2025 | The rules are that every mention by someone counts. Related markets have turned to yes. |
operation argument
Jeff Dorman, Arca’s chief investment officer, didn’t find this funny. He said crypto enthusiasts need to think hard about whether they think it’s “cute, smart, clever, that the CEO of the industry’s biggest company openly manipulated the market.”
Dorman added:
“After eight years of working tirelessly to educate institutional investors on the value of crypto investing as an investable asset class and help them feel comfortable in the industry, it’s not fun for one of our supposed ‘leaders’ to publicly ridicule the industry with nonsense like this.”
Evgeny Gaevoy, CEO of Wintermute, questioned whether scale matters.
Dorman argued that if Jamie Dimon joked on JPMorgan’s earnings call that he bribed the Knicks with a $10,000 bet, the issue wasn’t the amount but the embarrassment of a CEO of a regulated financial company treating the market like a toy.
Gayvoy countered that people in regulated finance take speech too seriously and cited Elon Musk as a comparison.
“Elon does the same thing that Brian does 100 times a day. And I’m pretty sure that what Brian did was a joke and not some kind of manipulation. If there’s something that shows the human side of him.”
Dorman concluded the exchange by distinguishing between technology and financial companies.
“Elon runs a technology company, not a financial company. And like it or not, Coinbase is not only a financial company, but a leading financial company in an industry already plagued by immaturity, manipulation, and corruption.”
He claimed that he will be asked about this by institutional investors “more than 50 times” in the next year, adding that Coinbase has put off conversations with actual investors and doesn’t even know about it.
Legal issues are narrower in scope than reputational issues.
Mr. Armstrong’s words do not imply a securities market manipulation standard because the contracts referenced are not securities and the CFTC’s event contract rules do not prohibit subject matter from influencing trivial binary outcomes.
As a result, allegations of manipulation have become about norms and optics rather than law.
Prediction market builder’s perspective
Prediction market analysts and platform operators treated this episode as inevitable.
Aaron, who developed the tool Carcinomics, who Carsi credits as an “early collaborator,” commented:
“LOL, I’m glad Coinbase made the move because this was bound to happen sooner or later.”
Tyrael, COO of Predict Shark, agrees:
“Yeah, we’ve been joking about it for a long time, but it’s crazy that it actually happened for the first time on the earnings call, haha, that’s Chad’s move.”
The designer’s view is that the mention market is a low-stakes novelty gamble, rather than serious information aggregation, and Armstrong created subtext text.
Design leads to just such an outcome when the market allows subjects to control the outcome by simply saying the word.
Armstrong’s comments were no coincidence. He admitted that he was tracking the market and worked it out on purpose. This means he understood the mechanism and chose to cause it.
Whether it’s harmless fun or a reputational failure depends entirely on the person evaluating it. For a crypto-native audience, this stunt is funny because it highlights the absurdity of betting on which buzzwords a CEO will use.
For financial institution allocators already skeptical about the maturity of cryptocurrencies, this is another data point that suggests industry leaders are not taking their role seriously.
The nearly $90,000 stake has nothing to do with either interpretation. The question is whether CEOs of regulated financial companies should publicly demonstrate that they can rig markets, even in markets that were intended to be rigged, and whether doing so advances or undermines the legitimacy of the industry.