This paper proposes a denomination protocol that enables Bitcoin to function as a stable unit of account without modification to the underlying protocol. Transaction amounts are expressed using a cumulative historical average of daily Bitcoin prices, producing a unit whose purchasing power changes negligibly from day to day. Each calendar day constitutes a timeblock whose price, once recorded, becomes progressively more permanent as subsequent days are added to the average. The denomination requires no token, no issuer, no reserves, and no trusted third party. It is computed from publicly available trade data using a transparent methodology that any participant can independently verify and reproduce. The result is a stable Bitcoin denomination whose resistance to disruption strengthens over time through a deterministic mathematical formula.
Bitcoin [1] created a peer-to-peer electronic cash system that requires no trusted third party. The network has operated continuously since January 2009, settling transactions without reliance on financial institutions. Yet Bitcoin has not achieved widespread adoption as a medium of everyday exchange. The barrier is not technical. The network works. Lightning provides throughput. Settlement is secure and final. The barrier is that Bitcoin's fiat-denominated price is volatile, and this volatility makes it impractical for the daily commerce that constitutes the bulk of economic activity.
Stablecoins emerged to address this gap by pegging digital tokens to fiat currencies. In doing so, they reintroduce the trust dependencies Bitcoin was designed to eliminate: centralized issuers who can freeze accounts, reserves that must be audited, and continued operation of entities subject to regulatory and counterparty risk. Algorithmic approaches have demonstrated catastrophic failure modes [2]. Fiat-backed stablecoins function as digital dollars routed through additional intermediaries.
What is needed is a way to express Bitcoin's value that is stable enough for daily use while remaining entirely Bitcoin-native. This paper proposes a denomination protocol that achieves this through a cumulative historical average of daily prices. No new token is created. No reserves are held. No entity is trusted. The protocol is a standard for expressing value — a unit of account that any wallet, merchant, or payment system can adopt independently.
The system depends on a single daily input: a standardized Bitcoin price for each calendar day, designated the Bitcoin Average Daily Price (BTCADP). The BTCADP is denominated in United States Dollars and covers the 24-hour UTC window from 00:00:00.000 through 23:59:59.999. The full specification is published separately [3].
For each qualifying exchange, a volume-weighted average price (VWAP) is computed from all BTC/USD trades during the window:
The daily BTCADP is the 25% trimmed mean of qualifying exchange VWAPs. Exchanges are sorted by VWAP, the lowest and highest quartiles are removed, and the arithmetic mean of the remaining values is taken:
Each exchange contributes exactly one VWAP regardless of its reported volume. Equal weighting limits the maximum influence of any single exchange to 1/n of the untrimmed set, and the trimmed mean ensures that outlier values are excluded entirely.
BTCC (Bitcoin Currency) is defined as a denomination of Bitcoin whose fiat price on a given day is the arithmetic mean of every historical BTCADP value from the genesis block to the present:
Where N is the total number of days in Bitcoin's history through the previous completed day. At the start of each UTC day (00:00:00.000), the BTCC price is recalculated to incorporate the just-completed day's BTCADP. This updated price is then locked for the following 24 hours.
The sensitivity of the BTCC price to each new BTCADP value is:
As N grows, this sensitivity approaches zero. As of early 2026, N exceeds 6,200. A day in which Bitcoin's price moves 10% produces a change in the BTCC price of less than 0.01%. A 40% single-day crash shifts the BTCC price by approximately 0.04%. These are mathematical properties of cumulative averages. They do not depend on market conditions, assumptions about future prices, or the continued operation of any institution.
Bitcoin's blockchain achieves immutability through proof-of-work. Each new block cryptographically seals the one before it, making reversal exponentially more costly as the chain grows. A transaction buried under enough blocks is considered practically irreversible — and with each additional block, reversal becomes exponentially less plausible.
The BTCC denomination exhibits an analogous property. Each UTC day constitutes a timeblock: a single day's BTCADP value that, once the day closes, is permanently recorded into the cumulative average. Like a block on the chain, a timeblock becomes more immutable over time — not because it is buried under computational work, but because it is buried under subsequent timeblocks.
This produces an immutability gradient. Recent timeblocks have measurable influence on the BTCC price. Older timeblocks have been so thoroughly absorbed into the average that no plausible market event could meaningfully alter their contribution. Every new timeblock simultaneously records a new day's price and reinforces the permanence of every day that came before it.
Bitcoin's blockchain can be understood through three physical dimensions. Blocks represent Space: discrete digital structures in which transactions are recorded and preserved. Proof-of-work represents Energy: the expenditure of computational energy that secures those blocks and makes them irreversible. Bitcoin Timeblocks represent Time: the daily accumulation of price across Bitcoin's entire history, each day's value permanently absorbed into the cumulative average.
Blocks encode what happened. Proof-of-work ensures it cannot be undone. Timeblocks record what Bitcoin was worth when it happened. Space, Energy, and Time — three dimensions of the same network.
Three properties govern the stability of the BTCC price:
Monotonically decreasing sensitivity. The impact of each new BTCADP on the BTCC price is exactly 1/(N+1) of the difference from the current average. As N grows, this sensitivity approaches zero. The denomination becomes more stable with each passing day, permanently and irreversibly.
Bounded response to shocks. With N exceeding 6,200, no single day can move the BTCC price by more than approximately 0.016% of the shock's magnitude, regardless of how extreme that shock is.
Slow-moving trend. A flash crash in which BTC drops 40% in a single day shifts the BTCC price by approximately $6 — a change of 0.04%. A prolonged bear market in which BTC remains at $20,000 for three years produces less than 5% total change in the BTCC price over the entire period.
Bitcoin's price history spans multiple periods with different data characteristics. The BTCADP specification [3] defines four eras. Era 0 (January 3, 2009 – July 17, 2010): no market existed; the BTCADP is defined as $0.00 for all 561 days. Era 1 (July 18, 2010 – February 24, 2014): Mt. Gox was the dominant or sole exchange; single-source VWAP, flagged accordingly. Era 2 (February 25, 2014 – December 31, 2017): multiple exchanges, confidence transitions from reduced to full. Era 3 (January 1, 2018 – present): full trimmed mean methodology with consistent qualifying exchanges.
The BTCADP derives its manipulation resistance from reinforcing design choices: the trimmed mean discards the highest and lowest quartile of exchange VWAPs; equal weighting ensures that fabricated volume confers no additional influence; the price coherence filter iteratively removes any exchange whose VWAP deviates more than 5% from the median.
Even a successfully manipulated BTCADP has limited effect on the BTCC price. A single manipulated day shifts the cumulative average by at most 1/(N+1) of the difference. With N exceeding 6,200, an attacker would need to sustain manipulation across hundreds of consecutive days to produce a meaningful shift — a cost that is, for practical purposes, prohibitive.
BTCC requires no changes to the Bitcoin protocol. No soft fork, no hard fork, no new opcodes, no consensus rule modifications. The denomination operates entirely in the calculation layer. It defines a unit of account — a way to express and agree upon value — that is deterministic, publicly verifiable, and requires no real-time data beyond the daily BTCADP update at midnight UTC.
Any existing wallet, payment processor, or settlement infrastructure can adopt BTCC by implementing its own conversion logic against a single daily price. The BTCC standard specifies what the unit is and how it is computed. It does not prescribe how transactions are denominated, settled, or displayed.
The BTCC fiat price appreciates slowly over time as long as BTC spot exceeds the historical average. In BTCC terms, this constitutes mild deflation. Merchants pricing in BTCC will occasionally need to adjust prices downward.
If BTC spot were to fall below the BTCC fiat price for an extended period, the denomination would price goods at a premium to current market value. In practice this would require a decline of over 80% from current levels, sustained indefinitely — a scenario representing a fundamental crisis for Bitcoin itself.
Because the BTCC price updates only once per day, implementations that convert between BTCC and satoshis will experience intraday drift proportional to the day's BTC price movement. Managing this drift is an implementation-specific concern outside the scope of this paper.
This paper has described a denomination protocol for Bitcoin that produces a stable unit of account without introducing trust, issuers, reserves, or protocol modifications. The stability derives from a cumulative historical average that, by its mathematical nature, becomes more resistant to disruption with every passing day.
Bitcoin's blockchain records transactions in Space, secures them with Energy, and the BTCC denomination records their value across Time. The denomination asks nothing of the protocol and changes nothing about it. It requires only that the price history be computed honestly — and provides a transparent, reproducible methodology for doing so.
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