Temporal, the Firm Behind HumidiFi and Harmonic, Names Ex-Galaxy DeFi Head Michael Marcantonio CEO

Temporal, the Solana trading-infrastructure firm behind the HumidiFi prop AMM, the Harmonic block builder and the Nozomi transaction-sending service, has appointed Michael Marcantonio as chief executive. Marcantonio was most recently Head of DeFi at Galaxy Digital. Temporal announced the appointment on 27 October 2026, and its post on X the same day said he will lead growth across all three products, adding that "what we're building next is even bigger."

Who is Michael Marcantonio, Temporal's new CEO

Michael Marcantonio comes to Temporal from Galaxy Digital, where Temporal says he "led the firm's onchain trading and decentralized finance business." Galaxy's author page for Marcantonio says he oversees "Galaxy's onchain trading and decentralized engineering." Earlier at Galaxy he was Senior Corporate Counsel, helping lead its strategic mergers and acquisitions, and before joining Galaxy he was an M&A attorney at Kirkland & Ellis.

Marcantonio has argued the Solana case in public before. In October 2025 he set out his thesis for Solana as a home for tokenized securities trading on Lightspeed.

Temporal's announcement is signed by Ben Coverston and Jakob Povšič, who "will continue building alongside the engineers behind HumidiFi, Nozomi, Harmonic, and our validator infrastructure." The announcement does not say who held the chief executive title before Marcantonio.

Marcantonio's own comment in the announcement was about the team he is joining: "Pound for pound, Temporal has the most technically gifted team of engineers and quant traders on Solana." He added that the team "is at the cutting edge of redesigning market structures that have existed for more than a century."

HumidiFi, Harmonic and Nozomi: what Temporal runs on Solana

Temporal sits at three points in the path a Solana trade takes. It quotes prices through HumidiFi, it delivers transactions to the network through Nozomi, and it helps validators assemble blocks through Harmonic. Temporal describes these as liquidity and market making, order entry, and transaction scheduling and execution.

HumidiFi is a prop AMM, a trading venue whose prices come from a single professional market maker's own models. A standard AMM prices trades from a pool of liquidity that anyone can deposit into. Temporal says HumidiFi "has captured as much as 60% of Solana's total spot volume at its peak," without saying when that peak was or how it was measured. HumidiFi's own website gives a lower, undated share: roughly 35% of all spot DEX activity, and over 60% of activity among prop AMMs. Neither figure has been independently confirmed.

Harmonic, which Temporal presented at Breakpoint 2025, is a block builder: it orders transactions into blocks for the validators that run it. Temporal calls Harmonic "Paradigm-backed" and says it serves validators representing roughly 30% of Solana's total stake. Nozomi, by Temporal's count, has landed transactions representing tens of billions of dollars in volume. The firm also runs a validator business that it says supports more than $1.5 billion in staked assets.

Temporal's plan to expand beyond Solana spot trading into perps and options

Temporal says Marcantonio will lead its expansion into "fully decentralized, onchain perpetual futures, prediction markets, options, and structured products." The announcement names no products, launch dates or markets for any of these, so for now they are stated plans.

Temporal's announcement describes Marcantonio's mandate in business terms: to "turn Temporal's technical strengths into a broader financial business," pairing the engineering team with commercial and strategic leadership. The release presents his background as fitting that brief. It pairs his DeFi experience at Galaxy with his "expertise in corporate finance and strategic transactions," and his earlier roles were legal ones, as an M&A lawyer and then in-house counsel.

For Solana, the appointment matters because of how much of the trading stack one firm already touches. By its own figures, Temporal runs a venue that has handled a large share of spot volume, a block builder used by validators with about 30% of stake, and a transaction-landing service. Its new chief executive's stated job is to add perps, options and prediction markets on top. Temporal says it will keep publishing research and judge its progress by "whether markets on Solana become faster, more reliable, and fairer."