Privacy Policy

Last updated: February 2026

1. Overview

PredictionTax is designed with privacy as a core principle. We minimize data collection and process your information in your browser whenever possible.

2. Data We Do NOT Collect

  • Trade data: Your trades, positions, and P&L calculations stay in your browser's session storage. We do not transmit or store this data on our servers.
  • API credentials: Kalshi API keys and private keys are sent directly from your browser to our API route, used once for import, and immediately discarded. They are never stored.
  • Personal financial information: We do not collect your tax bracket, filing status, income, or any other financial details. These are processed locally in your browser.

3. Data We Do Collect

  • Payment information: When you purchase PDF forms, payment is processed by Stripe. We receive a confirmation of payment but do not see or store your credit card details. See Stripe's Privacy Policy.
  • Basic analytics: We may use privacy-respecting analytics (e.g., Vercel Analytics) to understand aggregate usage patterns (page views, device types). No personally identifiable information is collected.

4. How Your Data Flows

  1. Import: Your browser sends API credentials or CSV data to our server-side route. The route fetches data from the platform API, normalizes it, and returns it to your browser. No data is persisted on the server.
  2. Calculation: Tax calculations run entirely in your browser using client-side JavaScript.
  3. PDF Generation: When you download forms, your browser sends position data to our server-side route. PDFs are generated in memory and streamed back. No data is saved.

5. Session Storage

All trade data is stored in your browser's sessionStorage. This data:

  • Is only accessible in the current browser tab
  • Is automatically cleared when you close the tab
  • Can be manually cleared using the "Clear Data" button
  • Is never sent to our servers except when explicitly generating PDFs

6. Third-Party Services

  • Stripe: Payment processing. Stripe Privacy Policy
  • Vercel: Hosting. Vercel Privacy Policy
  • Kalshi API: Trade data import (only when you provide credentials)
  • Polygon RPC: On-chain data reads for Polymarket (public blockchain data)

7. Cookies

PredictionTax does not use cookies for tracking. We may use a theme preference cookie (light/dark mode) which contains no personal information.

8. Children's Privacy

PredictionTax is not intended for use by individuals under 18 years of age.

9. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be reflected by the "Last updated" date above.

10. Contact

For questions about this Privacy Policy, please reach out via the contact information on our website.