Privacy Policy

Who this covers

This policy governs the Arena website (arena-predictions.com), the Arena iOS app, and Arena’s command-line tool, MCP server and API. Arena is a paper-trading experience for prediction markets: you trade real, live market prices using virtual dollars. No real money is ever involved. Because there is no real-money trading, we do not collect the financial-account information a real brokerage or sportsbook would.

Information we collect

• Account & profile. Your display name, email address, and (optionally) a profile photo and the leagues you follow. If you answer the optional onboarding questions (why you joined and a monthly goal), we keep those answers private to your account. If you use Sign in with Apple and choose to hide your email, we receive only Apple’s private relay address, not your real one.
• Authentication. We use Supabase Auth with Sign in with Google and Sign in with Apple. We never see or store a password. You can also browse as a guest through a temporary anonymous session that is not tied to your name or email address until you choose to sign in. In the iOS app, the device identifiers described under “Advertising measurement” are still collected for guests.
• Activity in the app. Your paper trades and orders (including limit orders), positions and portfolio, verified pick records (receipts), lists and folders, watchlists, saved screens, head-to-head challenges, alerts, comments, and any referral code you redeem. All balances are virtual dollars with no real-world value.
• Command-line tool, MCP server & API. When you use them, we receive your sign-in, the parameters of each request (for example the market, side, size and price of an order), your IP address and standard technical headers, and a header naming the Arena package and its version. They do not read, upload or store your code, prompts, transcripts, models or files, and they contain no analytics or telemetry. We store API keys only as a hash, with their label, scopes, dates and when they were last used.
• Subscription status. Whether you have an active Arena Basic subscription (listed as “Arena Pro” on the App Store), and the related purchase and entitlement identifiers. Payments are processed by the Apple App Store on iOS and, on the web, by RevenueCat Web Billing using Stripe. We do not collect or store your card number or bank details.
• Device, log & usage data. Standard technical data such as IP address, device or browser type, app version, and interaction and diagnostic events, used for performance, security, and debugging. On the website we use Vercel Web Analytics and Speed Insights, which record page views and page performance. In the iOS app we record onboarding and funnel events with your account, including the market of your first trade.
• Cookies & local storage (web). To keep you signed in, remember preferences such as your theme, and support basic analytics. See “Cookies” below.

How we use it

We use your information to authenticate you; operate the app (your portfolio, orders, live markets, leaderboards, receipts, challenges, and alerts); process and validate subscriptions and entitlements; run the referral program; send you service messages and, if you enable them, push notifications when your picks settle; keep the service secure and debug problems; understand how people use Arena and produce statistics about that use; measure our advertising (see “Advertising measurement” below); and comply with legal obligations. Our staff may review individual accounts for these purposes and may use artificial-intelligence tools in that review, which can include account-level data.

Your trading strategies

Arena’s tools never collect the code, models or prompts behind your strategies. We do not study your trading to learn or copy your approach, no account operated by Arena trades on the basis of it, and we do not train artificial-intelligence models on it. The Terms of Use set this out in full, including what of your trading is public.

Legal bases (EEA / UK)

Where the GDPR or UK GDPR applies, we rely on: performance of our contract with you (to provide the service); our legitimate interests (to secure, maintain, and improve Arena); your consent (where required, for example certain notifications); and compliance with legal obligations.

How we share information

We do not sell your personal information.

What is public. Your account is private unless you make your profile public in Settings. While it is private, other users see only your display name, photo and comments on other people’s public trades, and that your account is private. If you make your profile public, your display name, photo, the leagues you follow, who you follow and who follows you (when they are public too), your comments, your ranking, your net worth and daily net-worth history, your current balance, your past results, runs and resets, your realized perps profit and perps rank, any Combine pass, and your closed trades that are not in a private list (market, side, entry price, time and result, which together show how much you staked) can be seen by anyone, including people without an account, and other users and their AI agents may copy them. While your profile is public, the size of a new trade can be inferred from changes in your balance, though not its market or side. Trades you place while your account is private stay hidden after you make it public, unless you choose to show them, and while any trade is hidden your balance, profit and rank stay hidden too. Your trades still count in Arena’s public usage totals, which never name anyone and never show a count below 5. Your open positions and trades in private lists are not shown to other users unless you choose to share them, for example by sharing a pick, making a list public, or joining a fantasy duel or league, and your onboarding answers are never shown to other users. The Terms of Use explain what is shown.

We share limited data with the providers below, and only as needed. Most process it only on our behalf. Meta, and the providers of AI tools our staff use, may also be able to use it under their own terms.

• Supabase: authentication, database, and file storage.
• RevenueCat: manages subscription access and entitlements. It also receives device identifiers, your IP address, your email address and, on the web, ad-click identifiers. It stores them with your subscription record and forwards them to Meta (the email in hashed form) for advertising measurement. It does not receive your trading activity.
• Stripe: processes card payments for web subscriptions on behalf of RevenueCat Web Billing.
• Apple: App Store payments, Sign in with Apple, and push delivery (APNs) on iOS.
• Google: Sign in with Google.
• Vercel: website hosting and privacy-friendly, aggregated analytics.
• Fly.io: the real-time market-data proxy that streams live prices.
• Meta: advertising measurement for the iOS app and for subscriptions bought after clicking one of our ads (see “Advertising measurement” below).
• Anthropic: AI tools our staff may use when reviewing how people use Arena, which can include account-level data, including trading data. Anthropic may be able to use that data under its own terms.
• Kalshi: provides prediction-market data. We send requests for market data, not your personal information; Kalshi’s own privacy policy governs any data it collects.

We may also disclose information if required by law or valid legal process, to protect the rights, safety, and security of Arena and our users, or in connection with a merger, acquisition, or sale of assets (in which case we will require the recipient to honor this policy).

Cookies & local storage

On the website we use cookies and browser local storage to keep you signed in, remember settings such as your theme, and measure usage. If you arrive from one of our Meta ads, the site also stores the ad-click identifier and campaign tags in local storage and, once you sign in, sends them to RevenueCat so that a web subscription can be matched to the ad. The website does not currently load Meta’s pixel or set advertising cookies.

Advertising measurement

The iOS app includes Meta’s SDK so we can measure which of our ads lead to sign-ups and subscriptions. It sends Meta app events such as app opens, sign-ups and trial starts. The app asks your permission through Apple’s App Tracking Transparency prompt and reads your device’s advertising identifier only if you allow tracking. Whether or not you allow it, we send RevenueCat your device’s vendor identifier, Meta’s anonymous ID for your install, your IP address and your email address, plus the advertising identifier if you allow tracking. RevenueCat stores them with your subscription record and sends Meta your trial conversions, subscriptions and renewals with these identifiers (your email only in hashed form), so that subscriptions can be matched to ads. On the website, if you arrive from one of our Meta ads, we keep the ad-click identifier and campaign tags and, after you sign in, send them to RevenueCat for the same purpose. Under some state laws, including California’s, this may count as “sharing” personal information for advertising. Turning off Allow Apps to Request to Track in iOS Settings keeps the advertising identifier from being read.

Data retention & deletion

We keep your information while your account is active and as needed to provide the service. You can delete your account at any time from within the iOS app, or request deletion from any platform by emailing support@zbgcllc.com. Deleting your account removes your profile, trades, orders, balances, lists, alerts, API keys, comments, follows and perps history. A few operational records keep your account ID afterwards: onboarding and funnel analytics events (deleted after 180 days), notification delivery logs and referral records. The subscription records we receive from RevenueCat also keep the email address, IP address, device identifier and country attached to your subscription. Deleting your Arena account does not delete the subscription record RevenueCat holds. Email us to request its deletion. We also keep information we must retain for legal, security, or fraud-prevention reasons, and statistics that no longer identify you. Backups and our providers’ logs are kept for a limited time.

Security

Data travels over TLS encryption and is stored on Supabase infrastructure that follows industry security standards. Because authentication is handled through Sign in with Google and Sign in with Apple, we never store a password. No method of transmission or storage is perfectly secure, but we work to protect your information and to limit access to it.

Your rights & choices

You may request access to, correction of, deletion of, or a copy of your personal data, and you may object to or ask us to restrict certain processing. Residents of California (CCPA/CPRA) have the right to know, delete, and correct their data, and to opt out of sale or sharing (we do not sell personal information; the advertising measurement described above may count as sharing), as well as the right not to be discriminated against for exercising these rights. Residents of the European Economic Area and the UK (GDPR) have the rights described above and the right to lodge a complaint with a supervisory authority. To make a request, email support@zbgcllc.com; we may need to verify your identity before acting.

You can make your account private or public in Settings on the website. It is private until you make it public.

International transfers

Arena is operated from the United States, and your information is processed and stored there. If you access Arena from outside the U.S., you understand that your information will be transferred to and processed in the U.S., and we take steps to ensure appropriate safeguards for such transfers where required.

Children

Arena is not directed to children under the age of 17, and we do not knowingly collect personal information from anyone under 17. If we learn that we have collected such information, we will delete it.

Changes to this policy

We may update this policy from time to time. When we do, we will revise the effective date above and, for material changes, provide a more prominent notice. Your continued use of Arena after an update means you accept the revised policy.

Contact

Arena is operated by ZBGC LLC. For any privacy question or request, email support@zbgcllc.com.

See also our Terms of Use and how Arena works. Questions? Contact support.