Yes. The probabilities come from live Polymarket prices and refresh every few minutes as trading moves them.

Are these real predictions?

They're the market's implied probabilities — what traders are collectively pricing — not a guarantee of any outcome.

No. Polymarket's public API is free and key-less; the saver only needs an internet connection.

Is this gambling or advice?

No. It's a read-only display of public market odds for curiosity, with no betting and no advice.

Yes — free, no download, in your browser.

Why is a share price treated as a probability?

Because a contract that pays one dollar if an event happens is worth roughly the chance of that event, if traders are rational and risk-neutral. In practice the match is approximate, especially for rare events.

What decides who wins a market?

Each market has a written rule naming the condition or source for settlement. Polymarket says outcomes are resolved by the UMA Optimistic Oracle: someone proposes an outcome and posts a bond, there is a challenge period, and disputes go to UMA's dispute process.

Which price does the board show?

Polymarket's documentation says the displayed price is the midpoint of the best bid and offer, or the last trade when the spread is wider than ten cents, so thin markets can look jumpy.

Prediction Market Screensaver

The Prediction Market screensaver is a live odds board of the world's biggest prediction markets — the probabilities the crowd is pricing on current events — from Polymarket's key-less public API. It's free, runs in your browser, display only, and ESC exits.

How the Prediction Market screensaver works

The saver fetches the most active markets from Polymarket's public API, with no key.

For each market it reads the current prices, which represent the crowd's implied probability of each outcome.

Markets are drawn as rows with the question and a probability bar — the odds the market is pricing right now.

The board is sorted by trading volume and refreshes every few minutes as the odds move.

How a prediction market turns bets into odds

A prediction market lets people trade contracts tied to the outcome of a future event. In the usual setup, a yes share pays one dollar if the event happens and nothing if it does not, so its trading price between zero and one is read as the crowd's probability estimate. A yes share at 70 cents suggests the market thinks the event is about 70 percent likely.

Polymarket's prices come from supply and demand between users, not from the company. According to its documentation, the displayed price is the midpoint between the best bid and best offer, or the last traded price when the gap between them is wider than ten cents. Each question carries a written resolution rule, and Polymarket says markets are resolved by the UMA Optimistic Oracle, which is why the wording of a rule matters.

Prices are not guarantees or neutral polls. Thinly traded markets can be moved by a single large trader, the participants are self-selected, and a wide bid-offer gap makes a displayed price a rougher estimate. Nothing here is a forecast you should rely on, and availability of such platforms varies by jurisdiction.

A worked example

The board reads off live questions with their odds — 57% on one outcome, a long-shot at 6% — the bars shifting as traders move the market, a snapshot of what the crowd thinks will happen.

Settings & tips

Sort by orders markets by today's volume or by overall size.
Accent recolours the bars.
Background sets the board backdrop.

Frequently asked questions

Are the odds live?: Yes. The probabilities come from live Polymarket prices and refresh every few minutes as trading moves them.
Are these real predictions?: They're the market's implied probabilities — what traders are collectively pricing — not a guarantee of any outcome.
Does it need a key?: No. Polymarket's public API is free and key-less; the saver only needs an internet connection.
Is this gambling or advice?: No. It's a read-only display of public market odds for curiosity, with no betting and no advice.
Is it free?: Yes — free, no download, in your browser.
Why is a share price treated as a probability?: Because a contract that pays one dollar if an event happens is worth roughly the chance of that event, if traders are rational and risk-neutral. In practice the match is approximate, especially for rare events.
What decides who wins a market?: Each market has a written rule naming the condition or source for settlement. Polymarket says outcomes are resolved by the UMA Optimistic Oracle: someone proposes an outcome and posts a bond, there is a challenge period, and disputes go to UMA's dispute process.
Which price does the board show?: Polymarket's documentation says the displayed price is the midpoint of the best bid and offer, or the last trade when the spread is wider than ten cents, so thin markets can look jumpy.

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