About This Tool
What This Tool Does
The Silver Bullion Stock Checker tracks real-time availability of physical silver bullion products across 14 online dealers in the US, UK, EU, and Asia. It provides an aggregate availability percentage as an objective market signal for precious metals supply.
The tool monitors 84 dealer/product combinations:
- 6 flagship silver products (Eagles, Maples, Philharmonics, Kangaroos, Britannias, Krugerrands)
- 14 bullion dealers across US, UK, EU, and Asia
Methodology
Data Collection
An army of cats in my basement checks dealer websites twice weekly (Tuesday and Friday evenings). For each product page, they detect availability status based on page content:
- In Stock: Product available for immediate purchase ("Add to Cart", "Buy Now")
- Low Stock: Limited availability indicated ("Low Stock", "Limited Availability")
- Out of Stock: Product unavailable ("Out of Stock", "Sold Out")
- Unknown: Status could not be determined (timeout, parsing error, ambiguous page)
Aggregate Calculation
The aggregate availability percentage treats "In Stock" and "Low Stock" as available. Formula:
Availability % = (In Stock + Low Stock) / Total Products ×
100
Example: If 70 of 84 products are available, aggregate availability = 83.3%
Update Frequency
Current (MVP): Manual scraping 2× per week (Tuesday &
Friday, 6:00 PM)
Future: Automated daily scraping via cron job
Limitations & Disclaimers
Data Accuracy
- Availability changes rapidly - data may be outdated within minutes
- Parsing errors possible due to website redesigns or A/B testing
- Dealer inventory systems may lag actual stock levels
- "Low Stock" detection is heuristic-based and may miss nuances
Coverage Gaps
- Tracks 14 dealers across 4 regions - does not represent the entire market
- Only tracks 1 oz coins/rounds - excludes bars, fractional, and numismatic products
- Does not track pricing, premiums, or shipping times
Technical Limitations
- Scraper may be blocked by dealer anti-bot systems
- Website downtime or rate limiting can cause "unknown" status
- SSL/TLS errors or network issues can prevent data collection
Not Investment Advice
This tool is for informational and educational purposes only. It does not constitute investment advice, financial advice, trading advice, or any other advice. Always conduct your own research and consult qualified professionals before making investment decisions.
Transparency Commitments
Open Methodology
This page documents the complete data collection and calculation methodology. No black-box algorithms or undisclosed data sources.
Staleness Warnings
The stock checker page displays warnings when data is >7 days old, ensuring users are aware of potential staleness.
Direct Dealer Links
Each product listing includes direct links to dealer product pages, allowing users to verify availability independently.
Privacy Protection
IP addresses are hashed with daily salts (GDPR compliance). Click tracking uses URL hashing. No personally identifiable information is stored long-term. See Privacy Policy for details.
Who Built This
This tool was developed to support the Generational Asset Fence (WF000GENAF) wikifolio portfolio strategy. It provides objective data on a key market signal: physical silver supply availability.
The tool is designed to be:
- Objective: Algorithm-based, no manual bias
- Transparent: Open methodology, disclosed limitations
- Citable: Timestamped data for analysis and reporting
Technical Stack
For those interested in the technical implementation:
- Frontend: Flask, Pico.css (semantic HTML, classless CSS)
- Scraper: Python, BeautifulSoup4, tiered anti-bot strategy system (requests, curl_cffi, nodriver)
- Storage: JSON files (simple, transparent, easily auditable)
- Security: IP whitelisting, Bearer token auth, rate limiting, CSP headers
- Hosting: Hetzner VPS (Austrian data center, GDPR-friendly)
Contact
Questions, feedback, or bug reports? See Impressum for contact information.