Crypto Gloss

Arthur Breitman

Arthur Breitman co-founded Tezos with his wife Kathleen Breitman, designing the protocol’s distinctive self-amending blockchain — in which the protocol itself can upgrade through an on-chain governance process where bakers (validators) vote on proposed amendments that are automatically tested on a testnet before activation, avoiding the contentious hard fork dynamic seen in Bitcoin’s block size debate — raising $232 million in Tezos’s July 2017 ICO (then among the largest ever), and subsequently managing a protracted governance dispute with the Tezos Foundation’s then-president Johann Gevers that delayed mainnet launch for over a year.

Background

Arthur Breitman holds a master’s degree in mathematics from École Polytechnique in France and a master’s in financial mathematics from New York University’s Courant Institute. He worked as a quantitative analyst at Goldman Sachs and a quantitative researcher at Morgan Stanley before pivoting to crypto research. Under the pseudonym “L.M. Goodman,” he published an early Tezos position paper in 2014 describing the self-amending blockchain concept.

Tezos Protocol Design

Breitman designed Tezos around several distinctive properties:

Self-Amending Governance

  • Bakers vote on proposals in a multi-period process (5 periods): Proposal → Exploration Vote → Cooldown → Promotion Vote → Adoption
  • Approved amendments are automatically activated after a testing period
  • This allows the protocol to evolve without hard forks — upgrades have been deployed continuously since mainnet (over 15 protocol upgrades by 2024)

Liquid Proof of Stake (LPoS)

  • No slashing in early Tezos versions (later upgrades introduced accusations and double-baking penalties)
  • Originally required 8,000 XTZ to be a baker; lowered over subsequent upgrades

Michelson Smart Contract Language

Tezos ICO and Governance Crisis

The July 2017 ICO raised $232 million in BTC and ETH — then one of the largest ICOs in history. However, the Tezos Foundation (established in Zug, Switzerland) was governed by Johann Gevers, who entered into a public dispute with the Breitmans over control of the foundation’s funds and the roadmap.

The dispute — which played out partly publicly — delayed mainnet launch by over a year (mainnet launched June 30, 2018, >12 months after ICO) and led to multiple class action lawsuits from investors alleging the ICO constituted an unregistered securities offering. Gevers eventually resigned from the foundation in February 2018.

History

  • 2014 — Publishes Tezos position paper under pseudonym “L.M. Goodman,” describing the self-amending blockchain concept
  • July 2017 — Tezos ICO raises $232M in BTC and ETH; at the time, one of the largest ICOs ever
  • Late 2017–early 2018 — Public dispute with Tezos Foundation president Johann Gevers over control of foundation funds; mainnet launch delayed; class action lawsuits filed
  • February 2018 — Gevers resigns from the Tezos Foundation; foundation restructured
  • June 30, 2018 — Tezos mainnet launches, over 12 months after the ICO
  • 2019–2024 — 15+ on-chain protocol upgrades deployed successfully; Tezos develops NFT (objkt.com) and DeFi (Plenty) applications using the self-amendment mechanism

Common Misconceptions

  • “Tezos has been stagnant due to its governance disputes.” — Despite the rocky start, Tezos has had one of the highest rates of successful on-chain protocol upgrades of any L1, demonstrating the self-amendment mechanism works in practice. Over 15 major upgrades have been deployed since mainnet.
  • “Arthur Breitman controls the Tezos Foundation.” — The Tezos Foundation is a Swiss nonprofit with an independent board. The Breitmans founded DLS (Dynamic Ledger Solutions), which contributed the codebase, but the foundation is structurally separate and operates independently of the founders.

Social Media Sentiment

  • r/tezos / r/CryptoCurrency: Breitman maintains a moderate public profile; Tezos has a dedicated community focused on self-amendment governance and NFT culture (objkt.com). The 2017 governance crisis is well-documented history rather than an active controversy.
  • X/Twitter (@murbard): Breitman posts technical observations and occasional market commentary; engagement is primarily within the Tezos technical community rather than mainstream crypto discourse.
  • Developer community: Michelson’s formal verification properties attract institutional DeFi researchers; Breitman’s cryptographic and mathematical background gives him credibility in technical circles.

Last updated: 2026-04

Related Terms

See Also

  • Tezos (XTZ) — the blockchain Arthur Breitman co-founded and designed; the protocol-level entry covering Tezos’s architecture and ecosystem
  • Kathleen Breitman — Arthur’s co-founder and wife; led the business and operational side of Tezos while Arthur handled protocol design
  • On-Chain Governance — the governance model Tezos pioneered; Arthur’s primary technical contribution to the blockchain design space

Sources