Legal
Privacy Policy
Short version: We collect minimal data. Analytics only run if you explicitly click "Accept" on the cookie banner. We never sell your data. Game progress is stored locally in your browser, and we don't keep any record of your games. If you join a waitlist for an upcoming feature, we keep your email address only to tell you when that feature launches.
1. Who We Are
Guess the Stock Chart ("we," "us," or "our") is operated at guessthestockchart.io. This Privacy Policy explains how we handle information when you use our daily stock chart guessing game.
For privacy questions, contact us at: guessthestockchart@gmail.com
2. Information We Collect
2a. Information you provide
We do not require account creation, login, or any personal information to play the game. You do not provide us with any personal data during normal gameplay. The one optional exception is joining a waitlist for an upcoming feature, described in 2f.
2b. Information stored in your browser (localStorage)
Your game progress, streak, win/loss record, and cookie consent preference are stored exclusively in your browser's localStorage under these keys: guessthestockchart_v1 and guessthestockchart_progress_v1 (Guess the Chart), minefield_puzzle_v3 and minefield_state_v2 (Market Minefield), ticker_streak_state_v2 (Ticker Streak), ratio_match_state_v2 (Ratio Match), and gtsc_cookie_consent. Your streak and win/loss record never leave your device unless you explicitly share your results. We cannot see, access, or modify this data.
To keep answers hidden until a game ends, each guess or answer you submit is checked by our Cloudflare Worker rather than in your browser. The request contains only your guess (a ticker or company name) and an encrypted game token, never your stats or any identifier. It's checked and discarded, not stored; like any request, it may appear in the Cloudflare logs described in 2d.
2c. Analytics (only with your consent)
If you click Accept on the cookie consent banner, we load Google Analytics (tag ID: G-8GCXFRNXBG) which collects:
- Pages visited and time spent
- General geographic region (country/city, derived from IP — IP address itself is anonymized)
- Device type, browser, and operating system
- Referral source (how you found the site)
- Game interactions (difficulty selected, share button clicks)
If you click Decline, no analytics scripts load. Your choice is remembered in localStorage. You can change your choice by clearing your browser's localStorage for this site.
2d. Server logs (Cloudflare)
Our infrastructure is hosted on Cloudflare. Cloudflare may automatically collect standard web server log data including IP addresses, request timestamps, and HTTP status codes for security and performance purposes. This is governed by Cloudflare's Privacy Policy. We do not have access to raw server logs beyond what Cloudflare exposes in aggregate form.
2e. Portfolio Analyzer
Files you add to the Portfolio Analyzer (positions exports and transaction histories) are read entirely inside your browser and are never uploaded. To look up public price history and fund data, the page sends only ticker symbols to our Cloudflare Worker, which fetches that public data from Yahoo Finance. Share counts, dollar amounts, cost basis, account names, and account numbers are never sent to us; like any request, the ticker lookups may appear in the Cloudflare logs described in 2d.
Your holdings (tickers, amounts, cost basis, and the account type such as "Individual" or "Roth IRA", with any account numbers removed) are saved in your browser's localStorage under portfolio_analyzer_holdings_v1 so you don't have to re-upload them; click Clear all on that page to delete them. Transaction histories are never saved. "Weights-only" share links contain tickers and percentage weights after the # in the URL, which browsers do not send to servers, and analytics on that page is configured to record the page address without it.
2f. Feature waitlists
Some upcoming features have an optional waitlist. If you join one, your browser sends your email address and the name of the feature to our Cloudflare Worker, which stores them, with the date you joined, in a Cloudflare KV storage space in our own Cloudflare account. Nothing else is stored with it: not your holdings, which never leave your browser, and not your IP address, although like any request the sign-up may appear in the Cloudflare logs described in 2d.
We use the address only to send you one email when that feature launches. It is never used for marketing or newsletters, and never shared, sold, or connected to anything else you do on the site.
3. How We Use Information
Analytics data (when consented) is used solely to:
- Understand how many people play the game and which features they use
- Identify and fix technical errors
- Improve gameplay and difficulty calibration
Waitlist email addresses are used only to tell you when the feature you signed up for launches (see 2f).
We do not use any data for advertising, profiling, or selling to third parties. The game is entirely free and ad-free.
4. Legal Basis for Processing (GDPR / EEA users)
If you are located in the European Economic Area (EEA), we process analytics data only on the basis of your explicit consent (Article 6(1)(a) GDPR), given when you click "Accept" on the cookie banner. You may withdraw consent at any time by clearing localStorage for this site. Waitlist email addresses are also processed on the basis of your consent, given when you submit the form; you can withdraw it at any time by asking us to remove your address. No other personal data processing occurs.
5. Cookies and Tracking Technologies
We do not set any first-party cookies. If you consent to analytics, Google Analytics may set third-party cookies (such as _ga and _gid) in accordance with Google's Privacy Policy.
All analytics are configured with anonymize_ip: true, meaning IP addresses are truncated before any processing.
You can opt out of Google Analytics at any time using the Google Analytics Opt-out Browser Add-on.
6. Data Sharing and Third Parties
We do not sell, rent, or trade your personal information. The only third-party data processor involved is:
- Google Analytics — only if you consent. Governed by Google's Data Processing Terms and Privacy Policy.
- Cloudflare — infrastructure provider that processes network traffic on our behalf.
Stock chart data is fetched from public financial data APIs (Yahoo Finance, Stooq) at the time you load the game. These APIs receive only stock ticker symbols — no user data is transmitted.
7. Data Retention
Analytics data is retained by Google Analytics for 14 months (our configured retention period). localStorage data persists until you clear your browser storage. We do not maintain any database of user activity on our servers. Waitlist email addresses are kept until we send the launch email for that feature and then deleted, or removed sooner if you ask.
8. Your Rights
Depending on your jurisdiction, you may have the following rights:
- Access: Request information about data we hold about you
- Deletion: Request deletion of your analytics data from Google Analytics, or removal of your email address from a waitlist
- Withdrawal of consent: Withdraw analytics consent at any time (clear localStorage)
- Objection: Object to analytics processing before consenting
To exercise these rights, contact us at guessthestockchart@gmail.com. For Google Analytics data deletion, use Google's tools or contact Google directly.
EEA users also have the right to lodge a complaint with their national Data Protection Authority.
9. Children's Privacy
The game is not directed at children under 13. We do not knowingly collect personal information from children. If you believe a child has provided information to us, contact us and we will delete it promptly.
10. Security
We take reasonable technical precautions to protect the site and its infrastructure, including HTTPS encryption for all traffic, security headers (HSTS, CSP, X-Frame-Options), and Cloudflare's DDoS and threat protection services.
11. International Transfers
If you use analytics, your data may be transferred to and processed in the United States by Google Analytics. Google participates in the EU-US Data Privacy Framework. If you are in the EEA and have concerns about this transfer, you may decline analytics.
12. Changes to This Policy
We may update this Privacy Policy from time to time. Material changes will be noted with an updated "Last updated" date at the top of this page. Continued use of the site after changes constitutes acceptance of the revised policy.