The Proof System
Every one of 3,220 datapoints can be independently verified. A direct URL, an integer page number, a verbatim quote. No exceptions.
Overview
Three fields that make every number verifiable
The proof system is not a feature we added after the fact. It is the foundational constraint the entire dataset was built around. If we cannot prove a number, we do not include it.
Every datapoint stores three proof fields:
proof_url
The direct URL to the exact document. Not a landing page. Not a search results page. Not a company's IR homepage. The URL for the actual PDF or HTML filing. If you paste this URL into a browser, you get the document the number came from.
proof_page
The integer page number within that document. “Page 47” means PDF page 47. Not “the appendix” or “the production table” — a specific integer. During our audit, we found and corrected hundreds of records that had stored strings like “Production Summary Table” instead of page numbers.
proof_quote
Verbatim text from that page that contains the number. Exactly as it appears in the document. No paraphrasing. No annotations. No formulas we constructed. If the document says “All-in sustaining costs per ounce of $1,444”, that is the proof_quote — the full sentence, exactly as written.
Example
What a proof block looks like
“Attributable gold production for the year ended December 31, 2024 was 5.9 million ounces.”
“Consolidated copper production totaled approximately 4.2 billion recoverable pounds in 2024.”
The Verbatim Rule
No constructed quotes
During our data audit, we found hundreds of proof_quotes that were not actually verbatim. They were constructed: addition formulas (“Mine A 50 koz + Mine B 40 koz = Total 90 koz”), conversion annotations (“[converted: 265 koz]”), year tags appended (“(FY2024)”), and multi-KPI pipe-joined strings (“gold 350koz | silver 12,000koz | copper 85kt”). None of these appear in the original documents.
We stripped all of these and replaced them with actual verbatim text from the source documents. If a document only breaks production down by mine with no company total, we use the Financial Highlights table from the annual report — which usually has consolidated totals in a single sentence.
The rule is absolute: the proof_quote must be a substring of the text on the specified page of the specified document. No exceptions. No annotations. No editorial additions.
Source Requirements
Primary sources only
“Sourced” means sourced to the original document, not sourced to someone who read the original document. One layer of transcription introduces one layer of potential error.
| Source Type | Exchange / Region | Status |
|---|---|---|
| Company website PDF | All | Primary (preferred) |
| SEC EDGAR (10-K, 20-F) | NYSE, NASDAQ, cross-listed | Primary |
| SEDAR+ (AIF, MD&A) | TSX, TSXV | Primary |
| ASX announcement PDF | ASX | Primary |
| LSE RNS via Investegate | LSE | Primary |
| JSE SENS | JSE | Primary |
| Wayback Machine | Dead URLs only | Fallback |
| GlobeNewsWire / PRNewswire | Wire services | Rejected (not primary) |
| HotCopper / MarketScreener | Aggregators | Rejected (not primary) |
| Reuters / Bloomberg / Yahoo | News sites | Rejected (not primary) |
Exchange Coverage
7 exchanges, 156 companies
| Exchange | Companies | Primary Filing | Example Companies |
|---|---|---|---|
| TSX | 57 | SEDAR+ (AIF, MD&A) | Agnico Eagle, Barrick, Teck, First Quantum |
| ASX | 39 | ASX announcements | BHP, Evolution Mining, Fortescue, Northern Star |
| NYSE | 22 | SEC EDGAR (10-K, 20-F) | Newmont, Freeport-McMoRan, Kinross |
| TSXV | 12 | SEDAR+ | Mako Mining, Guanajuato Silver |
| LSE | 11 | RNS via Investegate | Glencore, Anglo American, Antofagasta |
| JSE | 10 | JSE SENS | Gold Fields, Impala Platinum, Sibanye-Stillwater |
| NASDAQ | 5 | SEC EDGAR | Sigma Lithium, Uranium Energy |
In the Workspace
Click any value to see its proof
In every view — Rank, Grid, and Chart — clicking on any value opens the proof panel. The panel shows the full computation formula, the underlying values used, and for each value: the source URL (clickable), the page number, and the verbatim quote.
For Compare operations, you see proof for both the start and end values. For Range operations, you see proof for every intermediate value used in the calculation. Nothing is hidden.
See proof in action
Open the workspace, click any value, and verify it against the original source document.
Open Workspace