Firo (FIRO) is a proof-of-work cryptocurrency with optional private transactions using Lelantus Spark. Spark proofs can conceal transaction participants and amounts while allowing the network to validate the ledger. Transparent addresses remain available, so not every Firo transaction is private.
Market Data
| Metric | Value |
|---|---|
| Ticker | FIRO |
| Price | $0.8666 |
| Market capitalization | $16.62 million |
| 24-hour change | +1.2% |
| 24-hour trading volume | $137,361 |
| Circulating supply | 19.178 million |
| Total supply | 19.178 million |
| CoinGecko maximum-supply field | 21.4 million; see tail-emission qualification below |
CoinGecko snapshot checked 2026-10-24 03:26 UTC. Price, market capitalization, volume and supply figures can change. CoinGecko reports a 21.4-million maximum-supply field; Firo’s FAQ says tail emission of 1 FIRO per block begins after that threshold, so the field should not be read as a permanent cap.
How Firo privacy works
Firo combines proof-of-work mining with Lelantus Spark privacy features. Spark transactions use cryptographic proofs so the network can validate state while concealing transaction participants and amounts. Firo also retains transparent addresses for compatibility and other workflows; privacy depends on the address type and transaction path used.
2026 Spark security update
In August 2026, Firo disclosed a vulnerability affecting multi-input Spark spends and temporarily restricted Spark transactions to one input while a fix was prepared. Release v0.14.18.0 introduced the new spend format and scheduled normal multi-input spending to return at block 1,371,000, approximately September 4, 2026. Later v0.14.18.x releases continued hardening the wallet and validation code. The release notes say existing coins and keys did not require migration.
Tokenomics and supply
Firo’s FAQ describes a 6.25 FIRO block reward until the 21.4-million threshold, followed by a 1 FIRO-per-block tail emission. That means 21.4 million is not a permanent maximum if tail emission begins. CoinGecko’s 2026-10-24 snapshot lists 19.178 million circulating and total FIRO and displays 21.4 million as maximum supply; the protocol FAQ’s tail-emission description is the important qualification.
The same official FAQ gives conflicting masternode reward percentages in separate answers. This overview does not repeat a percentage split until the project reconciles those figures.
History
- 2016 — The project began as Zcoin and used the Zerocoin privacy protocol.
- 2020 — The project rebranded from Zcoin to Firo.
- 2024 — Lelantus Spark went live on Firo mainnet.
- 2026 — A security update temporarily limited multi-input Spark spending before a hard-fork release restored it.
Social Media Sentiment
A public Firo Forum discussion dated October 4–8, 2026 debated whether to reinstate a time-limited emergency switch for Spark. Several participants supported a temporary safeguard after recent security concerns; others warned that a core-team switch could centralize control or stop user transactions. This is one thread, not a representative poll; the captured page showed zero poll votes, so no poll result is inferred. Read the discussion.
Last updated: 2026-10
Related Terms
See Also
- What Are Zero-Knowledge Proofs — And Why Every Major Blockchain Is Building Around Them
- Why Smart Contract Audits Fail: What Post-Mortems Reveal About the Limits of Security Reviews
- How Do Crypto Bridges Work — And Why Are They Such a Hack Target?
- Swap crypto with ChangeNOW
Sources
- Firo FAQ — Privacy and Economics — Explains Spark privacy, the continued role of transparent addresses, and the documented emission schedule; its separate reward-share answers conflict.
- Firo v0.14.18.0 Release Notes — Documents the 2026 Spark mitigation, temporary single-input restriction and planned restoration of multi-input spending.
- Firo Core Releases — Shows the subsequent v0.14.18.x software releases, including validation and wallet hardening.
- CoinGecko — Firo (FIRO) — Provides the timestamped price, market capitalization, volume and circulating-supply snapshot above.