Reward users that did at least one trade that is 4 months at least, without requesting an specific volume of a trade, primarily those users tested the exchange on it’s earlier stage so they should be rewarded. 4 months before that’s before the speculations that has been going all over social media in regards to a token airdrop.
Reward users or take into account those who also did repeated trades within different days, maybe as a multiplier of the airdrop.
Reward those who also provided funds during the purchase of the IDO which funded the project during a horrible bear market after what happened with curve finance, they should also be taken into account or as a multiplier for the airdrop.
It should be a fair airdrop disregarding the volume but taking into account tx, maybe applying what Hop protocol did to disregard bots that just traded on the exchange in search for free money.
Best regards.