1. Acceptance of terms
By subscribing to, downloading, or running ArbTrader ("the Software," "the Service," "we," "us"), you agree to these Terms of Service. If you don't agree, don't subscribe or use the Software. If you're using ArbTrader on behalf of an organization, you're agreeing on its behalf and confirming you have the authority to do so.
2. What ArbTrader is
ArbTrader is self-hosted software that scans Kalshi and Polymarket for same-market and cross-platform pricing spreads in prediction markets, and displays the resulting opportunities — the legs, prices, and sizes — for you to review. Where you connect your own exchange credentials, the Software can submit orders on your instruction. ArbTrader runs on infrastructure you control; we do not operate it on your behalf, and we do not place trades for you.
3. Eligibility
You must be at least 18 years old and able to form a binding contract to use ArbTrader. You're solely responsible for confirming that you're legally permitted to trade on Kalshi and Polymarket from your location, and that doing so complies with the laws and regulations that apply to you. Prediction-market trading is regulated differently across jurisdictions and those rules change; using ArbTrader does not make you eligible for a platform you aren't otherwise eligible to use.
4. Not financial or investment advice
ArbTrader surfaces pricing information. Nothing it displays, and nothing we say about it, is financial, investment, legal, or tax advice, or a recommendation to enter any trade. You are solely responsible for every trading decision you make, whether or not you used ArbTrader to inform it.
5. Subscription, trial, and billing
ArbTrader is offered as a monthly subscription, currently $30/month after a 7-day free trial. Subscriptions are billed through Stripe. Unless you cancel before your trial ends, your subscription begins and you're billed automatically; unless you cancel a paid subscription, it renews automatically each month at the then-current price until you cancel.
You can cancel anytime; cancellation takes effect at the end of the current billing period and you keep access until then. Except where required by law, fees already charged are non-refundable, including partial months.
6. License and restrictions
While your subscription is active, we grant you a limited, non-exclusive, non-transferable license to download, install, and run ArbTrader for your own trading activity. You may not resell, sublicense, or redistribute the Software or its source, use it to build a competing product or service, or remove or alter any proprietary notices. This license ends automatically if your subscription ends or these Terms are terminated.
7. Your accounts, API keys, and funds
ArbTrader is self-hosted: it runs on your own machine or server, using your own Kalshi API credentials and your own Polymarket wallet key. We never receive, store, or have access to your credentials, your funds, or your exchange accounts. You are solely responsible for keeping your credentials and the environment ArbTrader runs on secure — we have no ability to reset, recover, or protect them for you.
8. Assumption of risk
You understand and accept that:
- Trading prediction-market contracts carries real financial risk, up to and including total loss of the amounts you trade.
- The order-placement code for both platforms has been built and reviewed but has not been exercised against live trading accounts at scale; bugs, timing issues, or unexpected platform behavior are possible.
- The two legs of a cross-platform trade are not placed atomically — one leg can fill while the other fails, leaving you with an unhedged position that ArbTrader does not automatically unwind.
- Displayed spreads use estimated, not live, fee figures, and can differ from your actual cost to trade.
- Software, exchange APIs, and market data can fail, lag, or go offline without notice, and any of those can affect a trade in progress.
You use ArbTrader, and act on anything it shows you, entirely at your own risk.
9. Third-party platforms
ArbTrader is an independent tool and is not affiliated with, endorsed by, or sponsored by Kalshi or Polymarket. Your use of those platforms is governed by their own terms, not these. We don't control, and aren't responsible for, their uptime, pricing, fees, rule changes, or decisions about your account — including if they restrict or terminate API access to tools like ArbTrader.
10. Disclaimer of warranties
ArbTrader is provided "as is" and "as available," without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, non-infringement, or that the Software will be uninterrupted, error-free, or secure. No advice or information you get from us creates a warranty not stated here.
11. Limitation of liability
To the maximum extent permitted by law, we are not liable for any indirect, incidental, special, consequential, or punitive damages, or for any trading losses, lost profits, or lost data, arising from your use of ArbTrader — even if we were advised of the possibility. Our total liability for any claim relating to the Software is limited to the subscription fees you paid us in the 3 months before the claim arose.
12. Indemnification
You agree to indemnify and hold us harmless from any claim, loss, or expense (including reasonable legal fees) arising from your use of ArbTrader, your trading activity, or your violation of these Terms or of any law or third-party platform's terms.
13. Termination
You may stop using ArbTrader and cancel your subscription at any time. We may suspend or terminate your access if you violate these Terms, don't pay applicable fees, or if we reasonably believe your use poses a legal or security risk to us or others. Sections that by their nature should survive termination — including Sections 8 through 12 — continue to apply after your access ends.
14. Changes
We may update these Terms or the Software from time to time. We'll post the updated Terms with a new "last updated" date; continuing to use ArbTrader after changes take effect means you accept them. If a change is material, we'll make a reasonable effort to notify active subscribers.
15. Governing law
These Terms are governed by the laws of the State of California, without regard to conflict-of-laws principles, and any dispute will be brought in the state or federal courts located in California. (Placeholder — set this to wherever you actually form your business, and confirm with a lawyer whether you want a mandatory arbitration and class-action-waiver clause here, which is common for SaaS terms but needs to be drafted correctly to be enforceable.)
16. Privacy
We collect the minimum needed to run the subscription — your email and payment details, handled by Stripe on our behalf — and don't collect your exchange credentials or trading data, which never leave your own machine. (This section is a placeholder. If you collect anything else — support emails, analytics, marketing signups — you should publish a separate, complete Privacy Policy; required outright if you have any EU/UK or California users, under GDPR and CCPA respectively.)
17. Miscellaneous and about this document
If any part of these Terms is found unenforceable, the rest remains in effect. These Terms are the entire agreement between you and us regarding ArbTrader, and supersede any prior agreements on the subject. You may not assign these Terms without our consent; we may assign them in connection with a merger, acquisition, or sale of assets.
These Terms are ArbTrader's general policy for using the Service and are not a substitute for independent legal, financial, or tax advice. They're a working document that covers the standard bases for a self-hosted software subscription connected to real trading platforms and real money, and may be revised as the Service and applicable law evolve — see Section 14. If you need advice specific to your situation, consult a qualified professional in your jurisdiction.
18. Contact
Questions about these Terms: [email protected] (update to whatever address you actually monitor).