Privacy Policy

Last updated: September 2026

1. Information We Collect

When you use Chart Library, we may collect:

  • Account information: Email address when you create an account
  • Usage data: Search queries, features used, and interaction patterns
  • Device information: Browser type, operating system, and IP address

2. How We Use Your Information

  • To provide and improve the Service
  • To process your searches and deliver results
  • To communicate with you about your account or the Service
  • To analyze usage patterns and improve the user experience

3. Data Sharing

We do not sell your personal data to third parties. We may share data with service providers who help operate the Service (e.g., hosting, analytics, payment processing), but only as necessary to provide the Service.

4. Third-Party Services

The Service uses third-party APIs (Anthropic for AI summaries, Polygon.io for market data) to provide functionality. Your queries may be processed by these services in accordance with their respective privacy policies.

5. Cookies

We use essential cookies to maintain your session and preferences. We may also use analytics cookies to understand how the Service is used. You can disable cookies in your browser settings, though this may affect functionality.

6. Data Retention

We retain your account information for as long as your account is active. Usage data is retained for analytics purposes and may be anonymized or deleted periodically. You can request deletion of your account and associated data at any time.

7. Security

We take reasonable measures to protect your information, including encryption in transit and at rest. However, no method of transmission over the Internet is 100% secure.

8. Your Privacy Rights (California Residents)

If you are a California resident, the California Consumer Privacy Act (CCPA) provides you with specific rights regarding your personal information:

  • Right to Know: You may request that we disclose the categories and specific pieces of personal information we have collected about you.
  • Right to Delete: You may request that we delete any personal information we have collected from you, subject to certain exceptions.
  • Right to Opt-Out: We do not sell your personal information. If this changes, we will provide a "Do Not Sell My Personal Information" link.
  • Non-Discrimination: We will not discriminate against you for exercising any of your CCPA rights.

To exercise these rights, contact us at [email protected]. We will respond to verifiable requests within 45 days.

9. Chart Casebook

Review workspace notes stay in your browser on this device unless you download or share them. Clearing browser storage removes the saved copy. We do not receive these notes through the workspace.

Chart suggestions are stored for editorial review, along with an optional email for follow-up. A suggested chart and question may appear in a future article; contact details remain private.

Casebook email subscriptions require separate consent and email confirmation. We store the email address and consent status and use Resend to deliver confirmation links and new articles. Every article email includes an unsubscribe link. Existing account and newsletter subscriptions do not enroll you in the Casebook. Unconfirmed requests expire after 24 hours and are removed after seven days when they have never been confirmed. Keyed hashes used for form rate limits are removed after about two days by the delivery job.

Publishing-desk drafts, source notes and revision history are saved to the editor account. They remain private until the editor publishes the selected article content.

We count article views, engaged reads, comparison use, searches and subscriptions as daily totals for each public article. Article links may carry a public article reference so a later search or subscription can be counted. This adds no reader identifier, cookie, individual browsing history or email-open pixel. Search attribution stays in page memory for up to 30 minutes; subscription confirmation may carry the public article reference in its email link. We respect Do Not Track and Global Privacy Control. Daily totals are retained for 180 days. The existing keyed rate-limit hashes protect the count endpoint and expire after about two days.

You may request removal of a chart suggestion or subscription record using the contact below.

10. Contact

For privacy-related inquiries, contact us at [email protected].