Fernando Martinelli

Fernando Martinelli is a software engineer and entrepreneur who co-founded Balancer Protocol alongside Mike McDonald — creating an automated market maker that extended the two-token, equal-weight pool pioneered by Uniswap into a flexible, multi-asset framework capable of supporting up to eight tokens at arbitrary weight ratios. Martinelli's insight was that a liquidity pool with custom weights behaves mathematically like a constantly rebalancing portfolio, allowing liquidity providers to maintain a target asset allocation while earning trading fees from the arbitrage activity that keeps the pool balanced.

Before founding Balancer, Martinelli worked in software development and was involved in multiple technology ventures. He encountered the DeFi ecosystem as it was beginning to take shape in 2018 and 2019 and identified the fundamental constraint in Uniswap's design: the requirement that every pool hold exactly 50% of each of two assets was highly restrictive for use cases where participants wanted different exposure ratios, multiple assets, or the ability to create index-like positions on-chain.

Martinelli and McDonald published the Balancer whitepaper in September 2019, presenting the mathematical framework for a generalised constant-mean market maker — an AMM that maintains a target weight for each asset in a multi-asset pool. The constant-mean invariant extends Uniswap's constant-product formula to multiple assets with variable weights: where Uniswap enforces that the product of two token quantities remains constant, Balancer enforces that the weighted geometric mean of all token quantities in the pool remains constant.

The practical implication is powerful: a Balancer pool with 80% ETH and 20% DAI will, through arbitrage activity alone, rebalance itself continuously to maintain that 80/20 ratio as prices change. When ETH's price rises relative to DAI, traders will sell ETH into the pool and buy DAI out of it, profiting from the price discrepancy and simultaneously restoring the target 80/20 balance. Each of these rebalancing trades pays a fee to the liquidity provider — meaning the portfolio rebalances for free from the provider's perspective.

Balancer V1 launched on Ethereum mainnet in March 2020. Balancer V2, launched in May 2021, introduced a significant architectural redesign that Martinelli had designed to address V1's principal cost and flexibility limitation: all pool assets are now held in a single, shared Vault smart contract, while individual pool contracts contain only their mathematical logic. This separation reduces gas costs dramatically — tokens do not need to transfer between contracts during multi-pool trades, and 'internal balances' allow users and integrators to maintain token holdings within the Vault and execute complex strategies without token movements.

The Vault architecture made Balancer particularly attractive as infrastructure for other protocols to build upon. Rather than deploying a separate AMM, a new project could create a custom Balancer pool type — with its own pricing logic, fee structure, and operational rules — and access the shared liquidity and user base of the Balancer ecosystem immediately. This composable design has made Balancer one of the most widely integrated DeFi protocols in the ecosystem.

Balancer introduced the veBAL (vote-escrowed BAL) governance model in 2022, directly inspired by Curve Finance's veCRV system. BAL holders who lock their tokens in the protocol for up to one year receive veBAL, which grants boosted liquidity mining yields, governance voting rights over BAL emission direction, and a share of protocol trading fees. The veBAL model creates long-term alignment between token holders and the protocol's success — and initiates a 'Balancer Wars' dynamic analogous to the Curve Wars, in which protocols with pools on Balancer seek to accumulate veBAL to direct BAL emissions toward their own liquidity.

Martinelli has continued to lead Balancer's development and strategic direction, navigating the competitive landscape of multi-chain DeFi with a focus on modular, composable infrastructure that serves as a foundation layer for the broader ecosystem. Balancer's position as the preferred AMM infrastructure for liquid staking tokens, stablecoin stability modules, and on-chain fund management strategies reflects the durability of the weighted pool insight he and McDonald brought to DeFi in 2019.