Knowing that an address is a market maker rather than a whale changes what a transfer means. Nansen has spent years building the attribution database that makes that possible, and no free tool comes close on breadth or accuracy of labels.
What it is genuinely good at
Smart-money screeners that surface what labelled sophisticated wallets are accumulating; token god-mode views showing holder composition and flow; alerting on specific wallets or cohorts; and multi-chain coverage kept reasonably current. For funds monitoring positioning or researchers tracking capital rotation, that is a real workflow advantage.
What to be sceptical about
Labels are proprietary and cannot be independently checked. A wallet tagged as smart money earned that label from a model whose criteria you do not see, and following labelled wallets is a strategy that works until enough people do it. Treat the labels as a research prompt, not a signal.
Cost
Meaningful tiers start around $99 a month and rise steeply for professional features. For an individual investor, the combination of DefiLlama, Dune, Arkham's free tier and a block explorer answers most of the same questions at no cost, with more work. The subscription makes sense when your time is worth more than the difference.
Who should use Nansen
Professionals whose job is monitoring flows. Individuals should try the free tier and the free alternatives first, and subscribe only if a specific recurring workflow justifies it.