DeFi Summer refers to the period from approximately June to September 2020 when decentralized finance (DeFi) exploded from a niche corner of Ethereum into a mainstream crypto phenomenon. Triggered by Compound Finance’s launch of liquidity mining on June 15, 2020, the period saw unprecedented yield farming incentives, rapid protocol proliferation, the rise of “food token” projects, and the establishment of DeFi as a major pillar of the crypto industry. It is considered one of the most significant events in Ethereum’s history.
How It Started: COMP Liquidity Mining
On June 15, 2020, Compound Finance launched its COMP governance token and began distributing it to all borrowers and lenders on the platform. Crucially, COMP distribution was proportional to interest accrued — meaning the more you borrowed, the more COMP you earned.
This created the first large-scale liquidity mining program in DeFi:
- Users deposited stablecoins as collateral
- Borrowed against that collateral
- Redeposited the borrowed assets
- Repeated (leveraged farming)
- Earned COMP on every step
- COMP price rose as more people wanted in → yields appeared astronomical
Within days, Compound became the largest DeFi protocol by TVL. The game was on.
The Cascade
The COMP launch ignited a cascade of copycat and innovative protocols:
June 2020:
- COMP launch triggers the first mass liquidity mining rush
July 2020:
- YAM Finance launches with high-interest farming — gains $600M TVL in 48 hours before a bug drains the treasury, destroying the protocol
- Yearn Finance (YFI) launches with “fair launch” — zero pre-mine, no VC allocation, entirely community-distributed
August 2020:
- YFI price surpasses Bitcoin price — a meme and milestone that illustrated DeFi’s speculative energy
- SushiSwap launches as a Uniswap fork with SUSHI token farming — the “vampire attack” drains ~70% of Uniswap’s liquidity by offering farmers SushiSwap tokens for migrating
- Aave V1 renamed and gains significant traction with flash loans and interest rate model
September 2020:
- Uniswap launches UNI token with a retroactive airdrop (400 UNI to every past user ≈ ~$1,200 at launch); considered the largest airdrop in history at the time
- “Food tokens” proliferate: SUSHI, YAM, BASED, KIMBAP, HOTDOG, TENDIES — mostly scams or dead within days
Key Concepts Born in DeFi Summer
Yield Farming: The practice of actively moving assets between DeFi protocols to maximize returns, including liquidity mining rewards on top of underlying yields.
Liquidity Mining: Distributing a protocol’s governance tokens to users who provide liquidity — aligning incentives while bootstrapping TVL and decentralizing token ownership.
Vampire Attack: Deploying a protocol that incentivizes users to migrate their liquidity away from a competitor by offering rewards — SushiSwap’s attack on Uniswap being the canonical example.
Fair Launch: Originally distributing governance tokens with no pre-mine, no VC allocation, and no founder shares — YFI’s launch as the model case, viewed favorably by the community.
Food Tokens: Derogatory/affectionate term for the proliferation of copycat DeFi protocols named after food (SUSHI, YAM, PICKLE, CREAM, etc.) during the summer. Most were forks of Compound or Uniswap with minimal innovation.
Consequences
Positive:
- Launched DeFi as a serious sector with hundreds of billions in TVL by 2021
- Established yield farming, AMMs, flash loans, and governance tokens as DeFi primitives
- Attracted developer talent and capital to Ethereum
- Proved that community-owned protocols can generate real user adoption
Negative:
- Enormous Ethereum gas fees made DeFi unusable for small users (fees of $50-$500+ per transaction during peak demand)
- Most food tokens and copycat protocols went to zero; retail investors lost significant money
- Laid the cultural groundwork for “degen” behavior and reckless yield chasing that defined DeFi through 2022
Common Misconceptions
“DeFi Summer lasted all of 2020”
The most intense phase was June-September 2020. By October-November 2020, attention shifted to Bitcoin’s bull run toward $29,000 by year end and the anticipation of Ethereum 2.0.
“All DeFi Summer projects were scams”
The major protocols — Compound, Aave, Uniswap, Yearn — were legitimate and are still operating at scale. The scams were primarily the food token copycats. DeFi Summer produced real innovation alongside the noise.
Social Media Sentiment
DeFi Summer is remembered with a mix of nostalgia and cautionary emotion in the crypto community. For participants who profited (early yield farmers, YFI holders, Uniswap UNI airdrop recipients), it was a transformative wealth event. For late entrants who bought food tokens at peak prices, it was educational (painful). The period is cited constantly in discussions of DeFi history and protocol design. “DeFi Summer” is by far the most common label for this period; some analysts call it “Yield Farming Mania” but this is less common.
Last updated: 2026-04
Related Terms
Sources
- Schär, F. (2021). Decentralized Finance: On Blockchain- and Smart Contract-Based Financial Markets. Federal Reserve Bank of St. Louis Review.
- Buterin, V. (2020). Uniswap’s Retroactive Airdrop and What It Means for DeFi.
- The Defiant. (2020). The (De)Generative Era: A DeFi Summer Retrospective. The Defiant.