Bitcoin is the only major asset where any holder can cryptographically prove ownership without revealing their full balance, a counterparty, or a custodian's spreadsheet. Founded in 2022 in the United States by Sam Abbassi, Hoseki has turned that technical superpower into a product. Its white-label APIs let any institution or consumer-facing application generate real-time proof-of-ownership and proof-of-reserves backed by on-chain math rather than auditor PDFs.

For consumers, that means a borrower can prove to a lender they hold the bitcoin backing a loan, without ever giving up keys. For institutions, it means an exchange, ETF issuer, custodian or fund administrator can publish reserves in a format that regulators, auditors and end clients can verify themselves. Hoseki integrates this into existing regulated workflows rather than asking the industry to adopt a new tool — a deliberate, pragmatic design choice.

This is core Fulgur thesis territory. As bitcoin becomes collateral inside mortgages, prime brokerage, ETFs and corporate treasuries, the demand for cryptographic proof of solvency goes from nice-to-have to non-negotiable. Every FTX-shaped event in this market makes that case louder. Hoseki is positioning itself as the default plumbing for that proof — invisible to end users, indispensable to the institutions serving them.

Sam and his team have spent years thinking deeply about the intersection of bitcoin's transparency and the privacy users actually want. We are excited to back Hoseki as it builds the trust layer that lets regulated Bitcoin finance scale without re-importing the opacity of legacy banking.