Furnace Systems Raises $3.55M While Still in Stealth

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Furnace Systems Corp has raised $3.55 million, according to a recent SEC filing. Nine investors took part in the round.

Almost everything else about the company remains undisclosed. Furnace Systems is still in stealth and has not said what it is building.

What is known is the team and the timeline. Matthew Siff, Andrew Siff and Gabriel Rizk, all Brown University alumni, founded the company in 2025. It is based in New York, New York.

A raise of this size at the seed stage before any public product detail is not unusual for a founding team investors already know, though it does leave the rest of us waiting for the reveal.