Thumper finds the better price
Thumper sits in your browser and compares the price you're about to take on Polymarket, Kalshi and other markets with MagicMarkets — so you can see whether there's a better price before you trade.
Free · Chrome & Firefox · No account required
What is Thumper?
Thumper is a free browser extension from MagicMarkets. It opens as a panel alongside Polymarket, Kalshi and other markets, and shows the same position priced on MagicMarkets — line by line, in real time.
No new tab, no extra login. If MagicMarkets has the better price, Thumper flags it and shows exactly how much more you'd win.
Real-time comparison
MagicMarkets odds appear next to the market you're already viewing.
Better price alerts
A tag appears the moment we beat the price you're looking at.
Return calculator
See what a trade returns on each side before you commit.
Works where you trade
Polymarket today, more markets on the way.
Why traders install Thumper
Live
Prices update in real time as the market moves.
Better odds, flagged
A clear tag appears the moment MagicMarkets beats the price.
No new tab
Runs as a panel over the site you already trade on.
Free
No subscription, no account required to compare.
See both prices before you trade
Prediction markets don't always agree on price. Thumper compares the position you're about to take on Polymarket with the same position on MagicMarkets, so a small gap in odds doesn't quietly cost you on every trade.
Polymarket costs
$2,472
MagicMarkets costs
$2,400
Includes Polymarket's ~3% taker fee — $72 more for the same position.
Polymarket
Account limitedWho operates Thumper
Thumper is built and maintained by 3-102-947650 SRL, the same company behind MagicMarkets, incorporated under the laws of Costa Rica.
Our licence
MagicMarkets, the exchange Thumper compares prices against, is licensed in Anjouan, Union of the Comoros, under licence number ALSI-202607031-FI1.
See both prices before you trade.
Free to install, works in seconds, and it only ever tells you when there's a better price.