The Complete Guide to Balancer

Liquidez Programável

Pools podem ser criados com pesos de tokens, taxas de swap e lógica personalizados. Os desenvolvedores podem criar novas curvas AMM e, na v3, anexar hooks a tipos de pool existentes.

Gerenciador de Portfólio

Os arbitrageurs negociam contra o pool sempre que ele se desvia de seus pesos-alvo. Os provedores de liquidez (LPs) ganham taxas nessas negociações em vez de pagar pelo rebalanceamento.

Capital Eficiente

O Smart Order Router divide as negociações entre pools para encontrar um preço melhor. O Vault liquida apenas as transferências líquidas de tokens de um swap multi-hop, o que economiza gas.

The November 3, 2025 Exploit

On November 3, 2025, from 7:46 AM UTC, an attacker drained Balancer V2 Composable Stable Pools on several networks. Per Balancer's post-mortem (November 18, 2025), the exploit relied on incorrect rounding in the "exact out" swap path of stable pools: the required input amount was rounded down, so the caller underpaid. It needed three conditions at once: that rounding error, rate providers that added imprecision to the math, and a pool pushed into a very low liquidity state, which Composable Stable Pools allowed because their own pool token could be swapped in a batch. The post-mortem estimates the theft of user funds at $95 million; a December 2025 Balancer post puts the amount drained at $121 million.

Whitehats acting under the SEAL Safe Harbor Agreement recovered about $8 million, and StakeWise handled another $20 million in osETH and osGNO separately, per BIP-892. Newer V6 Composable Stable Pools were still inside their pause window and were paused within minutes. Balancer V3, every V2 weighted pool and the other V2 stable pool types were not affected, per the post-mortem. Independent analyses were published by Certora and Trail of Bits.

What Changed After the Exploit

• BIP-887 made V3 the only Balancer platform for new liquidity and disabled the V2 pool factories that could be disabled. Existing V2 pools still run, but Balancer encourages LPs to migrate.
• In March 2026, co-founder Fernando Martinelli announced the wind-down of Balancer Labs, citing the legal exposure created by the exploit. The protocol continues through the DAO, the Balancer Foundation and service providers.
• BIP-919 (BAL Tokenomics Revamp) passed on Snapshot in April 2026 with about 2.09 million votes for and 1.75 million against. It halted BAL emissions, discontinued veBAL, sent 100% of protocol fees to the DAO treasury and cut the protocol's share of V3 swap fees from 50% to 25%.
• On August 31, 2026, a rounding bug in legacy V1 pools (immutable 2020 code with no pause function) was exploited for about $1 million, per BIP-930.

O tipo de pool original. Cada token tem um peso (por exemplo, 80/20 ou 60/20/20) que define sua participação no valor do pool. O invariante do pool mantém constante o produto ponderado dos saldos dos tokens.

Um pool 80/20 ETH/USDC tem como objetivo manter 80% do seu valor em ETH e 20% em USDC. À medida que os preços de mercado se movem, os arbitrageurs negociam contra o pool até que ele retorne a esses pesos, e os LPs ganham uma taxa de swap em cada negociação.

O SOR consulta os pools do Balancer para encontrar o melhor caminho para uma negociação. Para swaps grandes, ele pode dividir a ordem entre vários pools para reduzir o impacto no preço. Os traders obtêm um preço melhor e mais pools registram volume.

Aggregators such as 1inch, ParaSwap and CoW Swap can also route trades through Balancer pools when they offer the best price, so pools receive volume from users who never open the Balancer app.

Introduzido no Balancer v2 em 2021, o Vault é um único contrato que detém e contabiliza os tokens de cada pool do Balancer. Os contratos de pool contêm apenas a lógica de precificação. De acordo com a documentação do Balancer, essa separação é o que torna possível o restante do design.

Uma troca multi-hop através do Vault transfere apenas a diferença líquida no final da transação, o que reduz os custos de gas. O Vault também oferece flash loans: tokens emprestados e reembolsados dentro de uma única transação.

Batch swaps run several swaps in one transaction and settle only the net token transfers. This makes routes with many hops cheaper than running each hop separately.

Flash loans let arbitrageurs borrow tokens from the Vault for the length of one transaction, use them to close a price gap between pools, and repay them before the transaction ends. This keeps pool prices close to the wider market. The same batch mechanism, combined with the rounding error, is what the November 2025 attacker used against Composable Stable Pools, per the post-mortem.

Pools Ponderados

The most general pool type, with up to eight tokens at custom weights, per the Balancer docs. It suits index-style portfolios that earn trading fees. A common setup is an 80/20 pool that pairs a protocol's governance token with ETH; Balancer's own 80 BAL / 20 WETH pool was still its largest on November 10, 2026, with $4 million in TVL, per DefiLlama.

Pools Estáveis

Built for tokens that trade near a 1:1 ratio, such as stablecoins (USDC, DAI, USDT) or liquid staking tokens against ETH (wstETH/WETH). Stable pools use a StableMath curve that keeps the price tight around the peg, so swaps between similar assets see less slippage. In v2 the composable variant, the Composable Stable Pool, is the type exploited in November 2025; V3 stable pools use a different codebase.

Pools Lineares (v2, obsoletas)

Um tipo de pool v2 que emparelhava um token base (por exemplo, DAI) com seu wrapper gerador de rendimento (por exemplo, aDAI da Aave) usando uma curva de precificação linear. As pools lineares foram os blocos de construção das pools impulsionadas v2. A Balancer as descontinuou após uma vulnerabilidade divulgada em agosto de 2023, conforme o fórum da Balancer. A v3 as substitui por buffers de liquidez.

Pools Impulsionados

As pools impulsionadas enviam a liquidez que não é necessária para swaps para um mercado de empréstimos como o Aave, de modo que os LPs ganham tanto taxas de swap quanto juros de empréstimo. Na v3, uma pool 100% impulsionada mantém todo o seu saldo em tokens que geram rendimento (cotas de cofre ERC-4626), e um buffer do token subjacente lida com os swaps, conforme a documentação da Balancer v3.

Como fornecer liquidez

Entendendo a Perda Impermanente

Impermanent loss (IL) is the gap between the value of your pool share and the value of simply holding the same tokens, when their prices move apart after you deposit. The larger the move, the larger the gap. Pool weights change how much IL you take (our impermanent loss guide works through more examples):

Tokenomics do BAL

veBAL System (Discontinued in 2026)

Until 2026, users obtained veBAL by providing liquidity to the 80/20 BAL/WETH pool and locking the resulting BPT for up to one year. A longer lock gave more veBAL, which decayed as the lock ran down. BIP-919 discontinued it: veBAL no longer earns fees or directs emissions, holders received a one-off payment of 500,000 USDC (BIP-920), and a buyback offer at net asset value, capped at 35% of the treasury, gave holders an exit, per the Balancer docs.

What Happened to Gauge Votes and Aura

As with Curve, a market for gauge votes had grown around Balancer: protocols paid veBAL holders, through platforms such as Hidden Hand, to vote emissions to their pools, and Aura Finance pooled veBAL on behalf of depositors. BIP-919 argued that this incentive market cost more in emissions than the fees it generated. With emissions and veBAL gone, that model no longer applies; check the Aura documentation for how Aura works today (see Sources).

Taxas de Swap

The base layer. Every trade through your pool pays a swap fee that stays in the pool, so the value of your BPT rises. Each pool sets its own fee within the range its pool type allows (in v3, 0.001% to 10% for weighted pools and 0.0001% to 10% for stable pools, per the Balancer docs). Nothing needs to be claimed. With $69 million of volume over 30 days across all of Balancer, fee income per dollar is modest.

BAL Emissions (Halted in 2026)

Until April 2026, LPs could stake BPT in a pool's gauge to earn weekly BAL rewards directed by veBAL votes. BIP-919 set the weight of every gauge type to zero, so new BAL rewards stopped. Any incentives still shown on a pool come from partner protocols, in their own tokens.

Rendimento da Pool Potencializada

In a boosted pool, liquidity not needed for swaps sits in a lending market such as Aave or Morpho and earns interest. That interest comes on top of swap fees, so one deposit earns from two sources, and it also carries the risk of the lending market.

Componibilidade & Estratégias Avançadas

BPT is a standard ERC-20 token, so it can be used in other protocols. Some common patterns, each with its own extra risk:

Quando os preços dos tokens se afastam da proporção na qual você depositou, sua participação no pool vale menos do que manter os tokens. A perda se torna permanente se você sacar nessa nova proporção. Pares voláteis carregam a maior IL. Pares correlacionados (stablecoins, LST/ETH) e pools ponderados que favorecem seu ativo preferido a reduzem.

Balancer's contracts have been audited by firms including Trail of Bits, OpenZeppelin and Certora (reports are in the GitHub repositories, see Sources), and the protocol runs a bug bounty. Audits did not prevent three incidents: in August 2023 a flaw in some v2 boosted pools was exploited; on November 3, 2025 a rounding flaw in v2 Composable Stable Pools led to an estimated $95 million theft; and on August 31, 2026 a bug in legacy V1 pools, which cannot be paused, was exploited for about $1 million. Check which pool version you use, avoid legacy V1 and V2 pools, and read the latest security notices on the forum.

Pool creation is permissionless: anyone can create a pool. Some pools hold tokens with malicious contracts, rebasing supply or fee-on-transfer logic that behave badly inside the Vault. Verify each token contract in a pool before you deposit. Small pools are also thin: with total TVL at $31 million, many pools hold only a few million dollars or less, so large deposits and withdrawals move the price.

Balancer Labs, the company that built the protocol, announced its wind-down in March 2026; development and operations now depend on the DAO, the Balancer Foundation and service providers funded by protocol fees. BIP-919 passed with a narrow majority (about 2.09 million votes against 1.75 million), so further changes to fees and governance are possible. Lower volume means lower fee income for LPs, and liquidity that leaves a pool widens its spreads.