CPI-U Historical Index
Consumer Price Index for All Urban Consumers (CPI-U), 1947 to present. This is the index FLAT tracks on-chain via the CPIOracle — every 12 seconds, FLAT adjusts its price to maintain purchasing power.
CPI-U Index Level
Purchasing Power: FLAT vs USD
What happens to $1.00 over time? USD decays. FLAT maintains.
How to read this chart: The gold line (FLAT) always stays at $1.00 because FLAT tracks CPI — your purchasing power is preserved. The red line (USD) shows what $1.00 from 1947 can actually buy today: just $0.07. Starting May 12, 2026, the FLAT oracle updates every ~12 seconds to maintain this peg in real-time on Ethereum.
CPI-U Key Milestones
| Date | CPI-U | $1 (1947) buys | Event |
|---|---|---|---|
| 1947-01 | 21.5 | $1.0000 | Series begins (post-WWII) |
| 1973-10 | 46.6 | $0.4609 | Oil embargo begins |
| 1980-03 | 80.1 | $0.2682 | Peak Volcker inflation (14.8% YoY) |
| 1982-07 | 97.5 | $0.2203 | Base period begins (1982-84=100) |
| 2000-01 | 168.8 | $0.1273 | Y2K / Dot-com peak |
| 2008-07 | 220.0 | $0.0977 | Pre-GFC peak |
| 2020-04 | 256.4 | $0.0838 | COVID lockdown low |
| 2022-06 | 296.3 | $0.0725 | Post-COVID inflation peak (9.1% YoY) |
| 2026-03 | 330.3 | $0.0650 | Latest BLS release |
How FLAT Tracks CPI On-Chain
The CPIOracle v3 contract (0xd4aA...c664) stores the BLS CPI-U value normalized to 18 decimals. When BLS releases a new monthly figure, the oracle owner calls updateCPI(newValue).
Instead of jumping instantly, the oracle interpolates linearly over 216,000 blocks (~30 days). This means FLAT's price adjusts smoothly every ~12 seconds — one Ethereum block at a time — eliminating front-running opportunities.
The result: 1 FLAT always equals 1 CPI-U unit of purchasing power. While USD loses value to inflation every month, FLAT holders maintain their real purchasing power indefinitely.
Data: U.S. Bureau of Labor Statistics, Consumer Price Index for All Urban Consumers (CPIAUCSL).
Retrieved from FRED, Federal Reserve Bank of St. Louis. Updated monthly after BLS release.