"How to judge a Polymarket wallet: ROI, CLV and sample size"
Every bet from every wallet is public on Polymarket. The temptation is obvious: find a wallet whose profit chart goes to the moon and follow it. But the profit chart is the worst way to judge a bettor. Here's what to look at instead.
Why the chart lies
Among thousands of wallets, some are just lucky. Have a thousand people flip a coin ten times and someone will hit ten heads in a row. That doesn't make them a coin-flipping expert.
Big profits also often belong to market makers, who earn the spread between buying and selling rather than picking winners. You can't copy that by copying their buys.
ROI and number of bets
ROI is profit divided by total amount wagered. +10% over 15 bets means almost nothing — it could be noise. +3% over 500 bets is serious.
Rule of thumb: under 100 settled bets, it's too early to conclude anything.
CLV: the strongest sign of skill
Closing line value compares the price a wallet paid with the price right before kickoff. A bettor who keeps buying below where the market closes is seeing something the market hasn't priced yet. CLV is much more stable than ROI and shows up within dozens of bets. More in what is CLV.
Consistency
Split the wallet's history in half. Profit in both halves is a good sign. All the profit from one hot week is more likely luck.
What else to check
- Sports. Sharp bettors are often good at one or two sports. Winning on the NBA says little about soccer.
- Live vs. pre-game. In-game prices move fast, so live bets are much harder to follow.
- Bet size. A bet 10× the wallet's usual size signals confidence, not certainty.
How PrognosX does it
Every wallet in PrognosX gets a Smart score from 0 to 100 that weighs how significant its profit is, its CLV and whether both halves of its history are positive — not just raw profit. Browse wallets and their bets in the whale feed.