Cookie Policy
Last updated: March 28, 2026
1. What Are Cookies
Cookies are small text files stored on your device when you visit a website. They help us provide you with a working, secure experience by remembering your login session and your preferences. Some cookies are essential for the platform to function; others help us understand how people use MasterTrading so we can improve it.
2. How We Use Cookies
We use three categories of cookies. Essential cookies are always active because the platform cannot function without them. Analytics cookies are only set if you give consent via our cookie banner.
Essential Cookies (Always Active)
These cookies are strictly necessary for MasterTrading to work. They handle authentication, security, and basic functionality. You cannot disable them. The legal basis for these cookies is legitimate interest (UK GDPR Article 6(1)(f)) and the ePrivacy exemption for strictly necessary cookies.
| Cookie | Provider | Purpose | Duration |
|---|---|---|---|
| sb-*-auth-token | Supabase | Keeps you logged in and authenticates API requests | Session / 7 days |
| sb-*-auth-token-code-verifier | Supabase | PKCE flow security — prevents authorisation code interception | Session |
| mastertrading_cookie_consent | MasterTrading | Remembers your cookie consent choice | 1 year |
| mastertrading_cookie_preferences | MasterTrading | Stores your specific cookie category preferences | 1 year |
Analytics Cookies (Require Your Consent)
These cookies help us understand how people use MasterTrading so we can improve the experience. They are only set if you click "Accept All" or enable analytics in the cookie settings. The legal basis is consent (UK GDPR Article 6(1)(a)). No special category data is ever included in analytics.
| Cookie | Provider | Purpose | Duration |
|---|---|---|---|
| ph_* | PostHog | Anonymous usage analytics — page views, feature usage | 1 year |
| ph_phc_*_posthog | PostHog | Distinct user identifier for analytics (anonymised) | 1 year |
Marketing Cookies (Not Currently In Use)
We do not currently use any marketing or advertising cookies. If we introduce them in the future, this policy will be updated and you will be asked for consent before any marketing cookies are set.
3. Managing Your Cookie Preferences
You can manage your cookie preferences in two ways:
- Our cookie banner: When you first visit MasterTrading, a banner appears asking for your consent. You can accept all, decline non-essential cookies, or customise your preferences. To change your choice later, clear your browser cookies for mastertrading.io and the banner will appear again on your next visit.
- Your browser settings: Most browsers allow you to block or delete cookies. Note that blocking essential cookies will prevent MasterTrading from functioning properly.
- Settings page (signed-in users): Once you have an account, you can change your analytics preference at any time from Settings → Privacy & Security. Your decision is stored against your account and applies across both the main app and the trade analytics surface.
If you declined analytics on the cookie banner before signing up, that decision carries through to your account. You will remain opted out of analytics until you actively change it from Settings → Privacy & Security.
If you decline analytics cookies, PostHog will not be loaded and no analytics data will be collected from your sessions.
4. Third-Party Cookies and Services
The third-party services that set cookies on MasterTrading are:
- Supabase — authentication cookies (essential). Data Processing Agreement in place. Data transferred to the US under EU SCCs + UK Addendum.
- PostHog — analytics cookies (consent-based). Data Processing Agreement in place. Data transferred to the US under EU SCCs + UK SCCs. No special category data is shared with PostHog.
- Sentry — error tracking runs always (essential / legitimate interest under UK GDPR Article 6(1)(f)) so we can detect and fix crashes that affect your account. We do not enable Sentry session replay — UI interactions are never recorded. Data Processing Agreement in place. Data transferred to the US under EU SCCs + UK SCCs.
- Stripe — may set cookies during the payment flow for fraud prevention (essential). Stripe's own privacy policy governs these cookies.
Each provider's cookies are governed by their respective privacy policies as well as our Data Processing Agreements with them.
5. Local Storage
In addition to cookies, MasterTrading uses your browser's local storage to remember your cookie consent choice and preferences. Local storage works similarly to cookies but does not expire automatically. Your consent preferences stored in local storage are treated with the same care as cookie data.
6. Changes to This Policy
We may update this Cookie Policy from time to time, particularly if we add new third-party services or cookie categories. Any changes will be posted on this page with an updated date. If we introduce new non-essential cookies, you will be asked for consent before they are set.
7. Contact Us
If you have questions about our use of cookies, please contact us at hello@mastertrading.io .
For broader questions about how we handle your personal data, see our Privacy Policy .