Summer Finance (Summer.fi)
Summary
Summer Finance, operating as Summer.fi, was a DeFi yield-optimization protocol that spun out of the Maker Foundation in 2021 and rebranded from Oasis.app in June 2023. On July 6, 2026, its Lazy Summer Protocol was exploited for approximately $6.04 million through a share-price manipulation attack that leveraged stale-valued tokens left over from the November 2025 collapse of Stream Finance. Following the exploit, the company announced it would cease operations, with the Summer.fi application shutting down on August 31, 2026, and governance of remaining vault infrastructure transitioning to the Lazy Summer DAO.
Connected Entities
1 entities- + 1 more
Timeline(13 events)
2021-06-01
Summer Finance (then Oasis.app) spun out from the Maker Foundation as an independent company.
Sunsetting Summer.fi and the Labs Company — Official Blog2023-06-01
Oasis.app rebranded as Summer.fi to reflect expansion beyond the MakerDAO ecosystem.
Summer.fi Team Page2025-11-04
Stream Finance disclosed approximately $93 million in losses; xUSD stablecoin fell approximately 77%, leaving Silo Varlamore USDC Growth vault tokens with stale on-chain valuations that were never corrected.
Stream Finance Stablecoin Plunges 77% — Decrypt2025-12-10
Lazy Summer Protocol launched SUMR Staking V2, enabling SUMR holders to earn staking rewards and USDC revenue distributions.
SUMR Staking V2 Blog Post — Summer.fi2026-01-21
SUMR governance token began trading for the first time.
Lazy Summer Governance Recap January 2026 — Summer.fi Blog2026-04-06
Attacker funded multiple wallets from identical sources, beginning a three-month accumulation phase targeting stale Silo Varlamore USDC Growth tokens.
Lazy Summer USDC Vault Exploit Post-Mortem — Summer.fi Official Blog2026-07-06
At 05:17 AM UTC, attacker executed a single atomic transaction exploiting the Lazy Summer USDC vaults, extracting approximately $6.04 million in depositor value via share-price manipulation using stale Silo Varlamore tokens and a ~$65.4 million flash loan.
Lazy Summer USDC Vault Exploit Post-Mortem — Summer.fi Official Blog2026-07-06
At 05:36 AM UTC, Blockaid identified the exploit and alerted the team. Guardian multisig progressively paused vaults across Ethereum, Base, Arbitrum, and Sonic through 11:38 AM UTC.
DeFi Protocol Summer.fi Halts Lazy Summer Vaults — CoinDesk2026-07-06
SUMR governance token fell more than 18% following public disclosure of the exploit.
Summer.fi Exploit $6 Million SUMR — BeInCrypto2026-07-08
Reporting established the causal link between the November 2025 Stream Finance collapse and the stale Silo token valuations that enabled the July 6 exploit.
$6M Lazy Summer Exploit Traces Back to November's Stream Finance Collapse — CryptoTimes2026-07-15
Summer.fi announced wind-down of operations, stating it had no viable path forward after the exploit eliminated team capital and protocol runway. Application set to shut down August 31, 2026.
Sunsetting Summer.fi and the Labs Company — Official Blog2026-07-30
Thirteen non-exploited Lazy Summer vaults across Ethereum, Base, Arbitrum, Sonic, and HyperEVM reopened for withdrawals. Deposit caps remain at zero; affected USDC vault users directed to claim via Merkl distribution.
All Lazy Summer Vaults Are Now Available for Withdrawal — Summer.fi Blog2026-08-31
Summer.fi application and support channels scheduled to cease operations. Protocol vault contracts remain on-chain under Lazy Summer DAO governance.
Sunsetting Summer.fi and the Labs Company — Official BlogDecision Log
- #1publish⛓ pending8/17/2026, 12:10:17 PMhash: AzP1kYYRunY3sGWfCMdTmgQs9xJNWahiDB5tc4imbRgE
12 of 13 cited source URLs have an Internet Archive snapshot.
model: claude-sonnet-4-6
generated: 8/17/2026, 12:10:09 PM
last updated: 8/17/2026, 6:39:34 PM
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