In the DeFi V1 era, decentralized finance mainly revolved around basic lending and token swaps. As adoption grew, limitations such as low capital efficiency and limited features became apparent.
The emergence of DeFi V2 marked a new phase of innovation, bringing more efficiency, flexibility, and user adoption.

II. Core Features of DeFi V2

1. Automated Market Makers (AMMs)

• The most iconic protocol of V2 is Uniswap V2.

• It introduced the constant product formula (x * y = k) for on-chain automated market making, removing the need for traditional order books.

• Anyone could become a liquidity provider (LP) and earn trading fees.

2. Upgraded Decentralized Lending

• Protocols like Aave V2 and Compound V2 enabled users to supply assets for interest or borrow against collateral.

• V2 introduced support for multiple assets and variable interest rates, making liquidity pools more efficient.

3. Liquidity Mining

• Projects incentivized liquidity providers with governance tokens.

• Compound’s COMP rewards in 2020 triggered the famous “DeFi Summer,” fueling massive liquidity inflows.

4. Composability (“Money Legos”)

• DeFi protocols could be combined seamlessly. For example:

  • Deposit assets into Aave to earn yield.

  • Use the interest-bearing token (aToken) in another protocol to farm additional rewards.

• This created a Lego-like financial ecosystem on-chain.

III. Key Protocols of the V2 Era

• Uniswap V2 – set the standard for decentralized trading.

• Compound V2 – pioneered liquidity mining, sparking an industry boom.

• Aave V2 – introduced flash loans and expanded collateral options.

• Curve Finance – optimized for stablecoin swaps with minimal slippage.

IV. Limitations of V2

Despite its breakthroughs, V2 had notable challenges:

1. Low capital efficiency – most liquidity remained idle outside of active trading ranges.

2. One-size-fits-all fees – trading pairs had fixed fee structures, lacking flexibility.

3. High gas costs – frequent on-chain interactions led to rising transaction expenses.

These shortcomings paved the way for V3 improvements.

V. Significance and Impact

• Sparked DeFi Summer: 2020 became the breakout year for decentralized finance.

• Enabled composable finance: V2’s interoperability laid the foundation for on-chain financial ecosystems.

• Built the groundwork: Many of the innovations in V3 and V4 were natural evolutions from V2’s foundation.

Conclusion

DeFi V2 marked the true beginning of decentralized finance adoption.
Through AMMs, decentralized lending, liquidity mining, and composability, it unleashed unprecedented growth in the crypto space.
While capital efficiency and flexibility remained limited, DeFi V2 established the cornerstone upon which V3 and V4 continued to evolve.