Rainbow

Rainbow is a self-custody crypto wallet built by Rainbow Studio Inc., available as a phone app for iPhone and Android, a desktop client and a browser extension. Inside the same app the operator markets sections for crypto, prediction markets and leveraged perps, positioning it as a single place to trade rather than a dedicated Polymarket terminal. Its Predictions section is where the Polymarket order flow attributed to this builder originates, sitting alongside crypto swaps and Hyperliquid-powered perps rather than existing as a standalone product.

The wallet keeps custody with the trader: Rainbow's own language says the keys and the crypto belong to the user, not the app. The Firefox browser extension is a separate Ethereum wallet, still in public beta, built for managing multiple seed phrases and wallets across layer twos such as Arbitrum, Optimism, Base and Polygon. Prediction market trading through this builder currently ranks #48 on attributed volume, with the largest share of last month's flow concentrated in esports.

A trader reaches Polymarket through Rainbow by opening the app's Predictions section on a phone, desktop client or browser extension, the same wallet already used for crypto and Hyperliquid-powered perps. There is no separate sign-up: the wallet a trader already holds handles the connection, and the extension's native support for Polygon and other layer twos means the account is already set up for the chain Polymarket settles on.

From there, the order itself goes into Polymarket's own order book rather than staying inside Rainbow. Rainbow attaches its own builder code to the order so Polymarket credits the resulting volume to this profile, which is how the figures on this page get attributed to Rainbow rather than to the trader directly. Whether that flow mostly opens new positions or closes existing ones shows up in the buy share, 72.4% of routed volume over the period covered.

What Rainbow does not do is hold the funds itself. The operator states plainly that the keys and the crypto stay with the user, so a position opened through the Predictions section remains controlled by the trader's own wallet rather than by Rainbow as custodian. The tradeoff sits in the browser extension, which is still a public beta and asks for permissions such as reading data on all websites and clipboard access to function inside the browser.

• Live pricing and charts

  Real-time prices and pro-level charts sit inside the same screen used to place a trade, so a trader can size an entry without switching to another app or site.

• Trade rewards program

  Every trade earns the operator's own RNBW token, and Rainbow Black upgrades let a trader auto-compound a share of their fees instead of just paying them.

• Self-custody key control

  Rainbow states that a trader's keys and crypto stay theirs, so the wallet is built to hold access rather than the trader's funds directly.

• One app across markets

  Crypto, Hyperliquid-powered perps and Polymarket predictions live inside the same phone app or extension, cutting the need for separate logins per market.

• Multi-chain wallet management

  The extension auto-discovers tokens and supports layer twos like Arbitrum, Optimism, Base and Polygon out of the box, useful for a trader juggling several wallets.

Mobile-first prediction traders

Someone already trading crypto from a phone can add Polymarket positions from the same Predictions tab instead of installing a dedicated terminal.

Existing Rainbow wallet holders

A trader who already keeps assets in Rainbow can route Polymarket order flow through a wallet they already trust rather than opening a new account elsewhere.

Self-custody focused traders

Anyone unwilling to leave funds with a custodial venue gets a wallet that keeps keys and crypto under their own control throughout.

Multi-market portfolio traders

Traders who also hold crypto and run Hyperliquid perps can manage all three inside one interface instead of switching apps mid-session.

Niche event market followers

Recent flow through this builder concentrates in esports, exemplified by Counter-Strike: magic vs K27 (BO3) - IEM Beijing: Global Qualifier Playoffs, fitting traders chasing narrower markets like esports outcomes.

Rainbow's own marketing talks about rewards, not price: every trade earns RNBW, and a Rainbow Black upgrade auto-compounds a share of a trader's fees back to them, but neither page states a fee rate for routing a Polymarket trade through this builder. Polymarket sets its own trading fee per market, and that fee is identical no matter which builder carries the order, so it isn't something Rainbow controls or discloses separately. Before sizing a trade here, a trader should check the fee shown inside the app at the point of execution rather than assume the rewards program offsets the full cost.

• Keeps custody with the trader, since Rainbow describes the keys and crypto as belonging to the user rather than the app.
• Puts crypto, perps and Polymarket predictions inside one phone app, desktop client or browser extension instead of several separate logins.
• Builds real-time pricing and pro-level charting into the same screen used to place a trade.
• Runs on iPhone, Android, desktop and as a browser extension, so the same wallet follows a trader across devices.
• Rewards every trade with RNBW and lets Rainbow Black members auto-compound a share of their fees rather than simply pay them.

• The operator publishes no fee schedule for Polymarket order flow, so a trader has to check the cost inside the app before each trade.
• The Firefox extension is explicitly labeled a public beta, and the developer acknowledges performance issues tied to it.
• The browser extension requests broad permissions, including access to data on all websites and to the clipboard, widening what a compromised install could reach.
• Weekly volume moved -70.9% against the prior week, with only 1 distinct trader active per day on average, a thin base worth watching before sizing around it.
• The trailing month's cohort is limited to 5 wallets, so recent activity reflects a small group rather than broad usage.

Custody stays with the trader: Rainbow describes itself as a wallet where the keys and the crypto belong to the user, not a custodial exchange holding balances on a trader's behalf. Transparency is mixed, the profile is verified on Polymarket, but the operator states no fee schedule for this order flow, so cost isn't disclosed up front. Operational exposure concentrates in the browser extension, still a public beta that requests broad permissions, including reading data on all websites and the clipboard, worth weighing against how much of a session happens in the browser versus the phone app.

Rainbow reads as a general wallet that added Polymarket trading, not a dedicated terminal built around it. The recent numbers, 21 fills last week from a cohort of 5 wallets, point to light and uneven usage rather than a steady desk-level flow. It suits a trader who already holds assets in Rainbow and wants prediction markets folded into that same app, alongside crypto and perps. It suits less well a trader chasing the lowest cost or the deepest, most consistent liquidity, since neither is something this builder currently demonstrates.

• What is Rainbow?

  Rainbow is a self-custody wallet from Rainbow Studio Inc. available as a phone app, desktop client and browser extension, with a Predictions section that routes Polymarket order flow under its own builder code.

• Is Rainbow safe to trade Polymarket through?

  Rainbow keeps custody of keys and crypto with the trader rather than the app, and its Polymarket profile is verified, but the browser extension is a public beta requesting broad site and clipboard permissions.

• What does Rainbow charge to trade on Polymarket?

  The operator publishes no fee schedule for Polymarket order flow. Polymarket's own per-market trading fee applies regardless of which builder carries the order, so check the fee shown in-app before trading.

• Does Rainbow hold my funds?

  No. Rainbow describes itself as a wallet where the keys and the crypto belong to the trader, not the app, so funds are not held in custody by Rainbow itself.

• What can I trade on Rainbow besides Polymarket?

  Rainbow's app also covers crypto swaps and leveraged perps powered by Hyperliquid, alongside the Predictions section used for Polymarket order flow, all inside one interface.

• Is the Rainbow browser extension the same as the phone app?

  No. The extension is a separate Ethereum wallet, still in public beta on Firefox, built for managing multiple wallets and layer twos, distinct from the phone app's Predictions section.

• What are Rainbow alternatives for trading Polymarket?

  Other builders on the leaderboard route the same Polymarket order book under their own codes; compare #48, routed volume and fill activity across builders before choosing where to route an order.