Samara’s Bitcoin CPI Reconstruction Shows a 5.44% Monthly Drop

A reconstruction of Samara Asset Group’s Bitcoin Consumer Price Index puts the U.S. consumer basket’s Bitcoin cost 5.44% lower in September than in August, while the company’s public page does not display a September U.S. reading.

The same calculation shows the basket cost 41.61% more in Bitcoin than in September 2025. These are reconstructed values, not readings published by Samara.

Samara describes the index, known as BTCCPI, as the U.S. consumer basket priced in Bitcoin (BTC). Its method uses the Consumer Price Index for All Urban Consumers (CPI-U), without seasonal adjustment, and BTC/USD prices. The public methodology does not specify the exact Bitcoin price observation convention.

For the reconstruction, CPI-U levels were 334.980 in August 2026, 336.940 in September 2026 and 324.800 in September 2025. The corresponding Bitcoin month-end closes were $78,548.63 on Aug. 31, 2026, $83,553.85 on Sept. 30, 2026, and $114,056.09 on Sept. 30, 2025. Dividing each CPI-U level by the corresponding Bitcoin price produces the reconstructed changes.

A lower BTCCPI reading means the basket costs fewer units of Bitcoin; a higher reading means it costs more. The index changes with both the dollar price of the basket and Bitcoin’s dollar price. From August to September, the CPI-U rose while Bitcoin’s month-end price also increased, producing a lower reconstructed cost in BTC. Over the year, Bitcoin’s September 2026 close was below its September 2025 close, contributing to the higher reconstructed BTCCPI.

The dollar-denominated CPI-U rose 0.6% from August and 3.7% over the 12 months through September. Those figures measure the basket in dollars, while BTCCPI expresses its cost in Bitcoin, so the measures can move in different directions. Samara Asset Group says, “Bitcoin’s volatility means that its short-term purchasing power can still fluctuate significantly.”