Crypto glossary
Retroactive airdrop
A retroactive airdrop rewards wallets with tokens for using a protocol before the token existed, based on activity recorded on-chain in the past.
In a retroactive airdrop, the token is distributed after the fact to people who already used the product. The best-known example is Uniswap's September 2020 airdrop, which gave 400 UNI to every address that had interacted with the protocol before a cutoff date, without any prior announcement. Later distributions by other DEXs, layer 2 networks and wallets followed the same logic: reward early adopters, decentralise ownership and turn users into stakeholders.
Those early surprises created a whole behaviour pattern. Users began interacting with tokenless protocols in the hope of future rewards, a practice known as airdrop farming, and projects responded with points programmes that make the expectation explicit and track activity in advance.
Because farming is now anticipated, retroactive airdrops increasingly go to professional farmers running many wallets, which pushes projects to add anti-Sybil filters and minimum thresholds. Recipients often sell immediately, and tax authorities in many countries treat airdropped tokens as income when received.
Example
A wallet that swapped on a DEX twice in 2020 later finds it can claim 400 governance tokens, as the protocol rewards every address that used it before a cutoff date.