Three steps.
One rule.

Every coffr pool mirrors one live Polymarket outcome with two sides, Yes and No. You deposit dollars on the side you believe. There is no price to pay and no share to buy: a dollar on Yes is a dollar on Yes.

The pool holds every deposit, on both sides, as a yield-bearing dollar token on Solana — tokenised short-term Treasury bills or over-collateralised lending. The whole pool earns together for as long as the outcome is open.

When Polymarket resolves the question, the pool closes. Every depositor on both sides can withdraw exactly what they put in. The interest the pool earned, less coffr's 10%, is split across the winning side in proportion to each deposit.

Pool

$1,000,000 · $600,000 on Yes, $400,000 on No

Time and yield

90 days at 5.0% APY

Interest

$12,329 earned · $1,233 to coffr (10%)

To winners

$11,096 to the Yes side, if Yes wins

$1,000 on Yes when Yes wins comes back as $1,018.49 — about 1.5× what the same money earns alone. $1,000 on No comes back as $1,000.00.

The fewer people on a side, the bigger its share if it wins. If 90% of a pool backs the favourite and it wins, they get about 1.1× normal interest. If the 10% are right, they split everything — about 10×. A small number either way.

You can withdraw your full deposit before the market settles. The interest your stake earned stays in the pool for the winners.

If Polymarket voids a market, nobody wins: every deposit comes back and the interest is returned pro rata, less coffr's 10%.

coffr is a waitlist today. The markets on the home page are live from Polymarket; the payouts are worked from their odds as illustrations. Read the risks before you deposit when it opens.