Methodology

What every piece has in common

Each visualization shows one dataset, or one pair of datasets, from a named public source. The sources, the preparation of each series, and the last period included are listed on the piece's own page. The visualization is a single self-contained file that can be opened directly or embedded on any page. No interpretation is offered; what the data shows is left to the viewer.

Format: line and sphere

The first pieces use one format. A series is drawn as a line, left to right, over twenty seconds. A second quantity is drawn as a sphere at the leading edge of the line. The animation holds briefly on the most recent period and loops. A scrubber pauses on any point.

The sphere's on-screen area is proportional to the second quantity, relative to the largest value in the series. A sphere with twice the area represents twice the value. This is the convention used by most bubble charts because people judge circles by area. Each piece also offers two alternatives in its controls: volume-proportional (radius scales with the cube root, which makes small values more visible) and logarithmic (each tenfold increase adds the same width). A three-pixel minimum keeps the smallest values visible.

Bitcoin market cap

In the current pieces the sphere is bitcoin's market capitalization: month-end price multiplied by the number of bitcoin mined to that date. Price comes from the Coin Metrics community dataset through spring 2026 and from published monthly closes after that. Coins mined are computed from the halving schedule, which matches reported circulating supply to within a fraction of a percent. Values before July 2010, when there was no meaningful market, are nominal placeholders of a fraction of a cent.

Series notes

• 10-year Treasury yield — monthly average of the constant-maturity yield. Federal Reserve Bank of St. Louis, FRED series GS10.
• Federal funds rate — monthly average of the effective rate. FRED series FEDFUNDS.
• Fed balance sheet — total assets, last Wednesday of each month. FRED series WALCL.
• Gold — US dollars per troy ounce, month end. 2009–2024 from historical London fix and spot records; 2025 onward from published monthly closes.

The final point in each series is the current period to date.

Update cadence

Series are refreshed after period end, typically in the first week of the following month. The "Updated" date on each page is the last period included.

Credits

Federal Reserve Economic Data (FRED), Federal Reserve Bank of St. Louis. Bitcoin price and supply data: Coin Metrics community data, used with attribution. Gold: LBMA and published spot records.

Accuracy

These are visualizations, not a data service. Values are rounded to the period shown, and the placement of a point within a period is a drawing convention rather than a claim about timing. If you spot an error, use the contact page; corrections are noted on the affected visualization.