Short answers to the questions people ask most about Nimb and Polymarket: what a price means, which wallet and currency you need, what it costs, where you can trade, how fresh the data is and what the risks are. Each answer comes first and links to the page that explains it in full.
About Nimb
What is Nimb?
Nimb is a free, independent map of Polymarket prediction markets. Each circle is a market, sized by the money traded on it and coloured by category. Open one to see what traders expect, how it moved, who holds the largest positions, and to place an order from your own wallet. More in about Nimb.
Is Nimb part of Polymarket?
No. Nimb reads Polymarket's public data and sends orders to Polymarket from the wallet you connect. Nimb never holds your money. See independence and business model.
Where does the name come from?
From the Latin nimbus, the cloud and the halo of light around it. Roman augurs read the future in the sky; Nimb reads the crowd's forecast in the shape of the money. Say it "nim", rhyming with limb. See about Nimb.
Is Nimb free?
Reading is free: the map, market pages and docs need no account and no wallet. Nimb earns only a small builder fee, included in the price you see, on orders placed through Nimb. See fees and all-in pricing.
Reading markets
What is a prediction market?
A prediction market is a market where people trade shares that pay $1 if an event happens and $0 if it does not, so the share price works as the crowd's estimate of the chance. Read what prediction markets are.
What does a price of 41% mean?
A share pays $1 if the outcome happens and $0 if it does not. If traders pay $0.41 for it, the market as a whole puts the chance at about 41%. It is the crowd's estimate, not a forecast by Nimb. See Polymarket odds explained.
What does "down 4 points" mean?
A point is one percentage point of chance. A market that moved from 45% to 41% is down 4 points, not down 4% (which would be 43.2%). See price charts.
What is market reading?
Market reading is working out what a prediction market's price, flow and holders say about an event, and how much to trust it. A price backed by a thin order book and a few wallets deserves less trust than one backed by deep, steady trading. Start with how to read a market.
What is the difference between spread and depth?
The spread is the gap between the best price to buy and the best price to sell; depth is how much money waits in the order book near those prices. A narrow spread tells you a small trade is cheap; depth tells you whether a large one will move the price. See spread and order book depth.
Are prediction markets accurate?
Often well calibrated, not infallible. Across many markets, outcomes priced near 70% tend to happen roughly 70% of the time, but thin markets, long shots and markets just before news can be badly off. See are prediction markets accurate?
How are the markets on the map chosen?
Every market is scored by how much money trades on outcomes that are still undecided, how deep its order book is, and how much it moved. A market must be open for trading, active enough, not already decided and cheap enough to trade. The top 110 per timeframe are shown, with room for each category in proportion to the money traded on its undecided outcomes (at least 4 markets, at most 40% of the map). See market selection.
What does alpha mean on Nimb?
In Nimb's docs, alpha means informational edge: something you know or have read in the data that the price does not yet reflect. It is not a promised return, and most apparent edge is noise or fees. See edge in prediction markets.
Wallets and money
Do I need an account?
Not to read. To trade, you connect a self-custody wallet; there is no Nimb account and no password. Polymarket sets up an account wallet (a Deposit Wallet) for your address the first time you trade. See connect your wallet to Nimb.
Which wallets work?
Browser wallets such as MetaMask, Rabby and Coinbase Wallet, and mobile wallets through WalletConnect, on the Polygon network. If you have none yet, create a crypto wallet first, and keep its recovery phrase offline. Then connect it to Nimb.
What currency do I need?
Polymarket trades in pUSD, a dollar token on Polygon backed by USDC. You can fund it by depositing USDC; deposits through Polymarket's bridge arrive as pUSD. Step by step: fund your wallet with USDC on Polygon.
Do I need POL for gas?
Usually not for trading: Polymarket's account wallets handle approvals and orders without gas through its relayer. You may need a little POL to move tokens yourself on Polygon. See funding your wallet.
Does Nimb hold my funds?
No. Your funds stay in your wallet and your Polymarket account wallet. Every order needs your signature, and Nimb cannot move or withdraw your money. See independence and business model.
Trading
What does it cost?
Reading is free. On an order you pay Polymarket's platform fee where the market has one, plus Nimb's small builder fee, included in the price you see. The amount you type is all-in: fees are folded into the shares, never added on top. See fees and all-in pricing.
What happens when I buy $100 of Yes at 41%?
In a typical fee-charging market you get about 237 Yes shares after fees. If it happens, they pay $237; if not, you lose your $100. Break-even sits slightly above 41% because fees are included. The ticket says this in one sentence before you sign. See the order ticket.
Can I trade from my country?
Not everywhere. Polymarket lists the United States, the United Kingdom, France and about 35 other countries and regions as close-only (you can close positions but not open new ones); sanctioned places are blocked completely. Nimb checks Polymarket's geoblock before every order. Do not use a VPN to get round it: it breaks Polymarket's terms. See eligibility and restricted countries.
What does close-only mean?
Close-only means you can sell or close positions you already hold but cannot open new ones. At the time of writing (2026-11-07), Polymarket applies it in the United States, the United Kingdom, France and about 35 other countries and regions. See eligibility.
Can I sell before the market resolves?
Yes. You can sell shares back into the order book at the current bid at any time while the market trades, taking a profit or cutting a loss. Selling into a thin book costs more, because each share fills at a lower bid than the last. The ticket shows what you receive before you sign. See selling and closing a position.
How does a market resolve?
When the event is decided, a result is proposed to Polymarket's oracle, UMA, and becomes final if nobody disputes it within a short challenge window. Winning shares then redeem for $1 each. See how markets resolve.
Data
How fresh is the data?
Prices stream live from Polymarket's order book. Volumes refresh every minute. The list of markets refreshes every 5 minutes in the app and every 6 hours on these pages. See data sources and freshness.
Why are some wallets left out of the holder lists?
A wallet holding both Yes and No in the same market has a position that cancels out. It is not a bet, so Nimb leaves it out of the leaning and the P&L. See net exposure and hedged positions.
Who are the "whales"?
A whale is a wallet with a very large position. Nimb shows the largest public holders per side as grey circles with green (Yes) or red (No) lines. Size is not skill: big holders can be wrong, hedged elsewhere or market makers, so read a large position as information, not as a signal to follow. See holders and wallet lines.
Why does "moves with / against" only show on 30D?
Short windows produce mostly false links. Nimb shows a link only on 30D, with at least 30 joint observations, a correlation of at least 0.5 either way, and only if it survives a leave-one-out test. Even then, some links are chance. See moves with and against.
Risk
Is this financial advice?
No. Nimb shows public data. Prediction markets are risky and you can lose your whole stake. See risks of prediction markets.
Can I lose more than I put in?
Not on a share you buy: the most you can lose on a purchase is the amount you paid. You can lose all of it, and fees, slippage and resolution disputes can add to the cost. See risks of prediction markets.
Where can I look up a term?
In the prediction market glossary: one-sentence definitions of over 80 terms, from spread and open interest to neg-risk and pUSD. For the shortest tour of the product, see How Nimb works.
Last reviewed 2026-11-07 · Data from Polymarket · Not financial advice · Nimb is not affiliated with Polymarket.