muni.llc

What is real here, and what is not

This site publishes United States interest rates and the open prices of prediction markets on where they go. It sells nothing, takes no positions, and is not investment advice.

Where the rates come from

Every rate is drawn from FRED, the Federal Reserve Bank of St. Louis's economic database, through its public CSV endpoint — which needs no key, which is why this pipeline cannot quietly break when a key expires. 214,270 observations across 18 series, the earliest from 1953, read on 8 September 2026.

FRED writes . for a day with no observation — a holiday, or a series that had not started. Those are dropped, never carried forward and never interpolated. A gap in a line here is a gap in the record.

The thing that is missing

There is no current municipal yield on this site, because there is no free public feed of one. The municipal series it does carry — the Bond Buyer 20-Bond GO Index — is real, runs from 1953, and was discontinued on 6 October 2016. It is drawn to that date and stops there. No line is extended, no current figure is inferred, and the municipal page leads with the discontinuation rather than burying it. The series in full.

Monthly means the last observation, not an average

The long history chart is monthly because seventy years of daily closes is more points than a screen can carry. Each monthly point is the last real observation of that month. It is never a mean: an average of a rate is a number that was never quoted to anybody, and putting it on a chart labelled with a date makes it look like it was.

Prediction-market prices are prices

The market pages show the last traded price of a contract that pays $1 if its statement turns out true. It is tempting to read 73 ¢ as "73% likely" and the exchanges encourage it, but the price also carries fees, the cost of tying up money until settlement, and how badly somebody wanted out. Thin markets move on one order. They are published here because they are real, observable and dated — not because they are correct.

How the charts are built

Every chart is drawn on the server as plain SVG, so the page is complete before any script runs and works with JavaScript off. Colours come from a validated categorical palette used in its documented order, capped at four series; every series is labelled at its own end so colour is never the only thing telling them apart, and every figure is followed by the same numbers as a table.

What this is not

Series18from FRED
Observations214,270daily and monthly
Maturities111 month to 30 years
Open markets149Kalshi + Polymarket