BYA
the BTC Accumulator
The yield becomes Bitcoin. The Bitcoin is never sold and never lent.
Two products, one discipline. Core converts each day's interest into Bitcoin, day after day. One spends three years of interest on Bitcoin on day one, as a discount, and lets the treasury leg rebuild the capital. Both run as public simulations: real market data, written rules, simulated capital — every number on this page comes from a ledger sealed on the blockchain each morning.
The interest buys Bitcoin, every day
The capital stays in short, low-risk yield instruments; the interest — and only the interest — buys Bitcoin.
The 2026 test: us, a Treasury, Bitcoin
Since January 5 the product runs for real, on simulated capital: never below 100, while Bitcoin lost as much as a third and a 10-year U.S. Treasury lost value too.
All three start at 100 on January 5, 2026. BYA Core: share value of the live paper test (sealed daily since July 23; the weekly phase before is reconstructed at real prices). Bitcoin: daily close in dollars, Coinbase. 10-year U.S. Treasury: value of a bond bought at par on January 5, coupons included, repriced every day at the official U.S. Treasury yield. Updated every morning; data in the public archive ↗.
What you are looking at
A simulation run by real rules: real market data, simulated capital. The capital sits in a basket of tokenized Treasury bills and savings tokens, each valued at its issuer's own on-chain redemption value — not at an aggregator's price. The interest buys Bitcoin daily; the Bitcoin is held, never sold, never lent.
Growth is measured by the share value, as in a fund: it started at 1.0000 on January 5 and the header shows where it stands today. The share has never closed below 1.0000 — through months in which Bitcoin fell by a third from its January price of $93,870. Since July 23 the simulation also accepts simulated subscriptions, which enter at that day's share value: new money earns no one a free return.
The sealed record, drawn
Every point below comes from the daily on-chain ledger, from July 23 to the latest seal. Green, left scale: the value of one share. Amber, right scale: the Bitcoin accumulated — a counter that never goes backwards. The chart redraws itself from the public archive ↗ on every visit: what you see is what was sealed.
The full series — JSON and CSV, every day since the first seal — lives in the public archive ↗: anyone can download it and redo the math.
The ledger writes itself
Since July 21 the ledger is systematic: a rules-based process runs every morning with no human hands on it. Four acts:
Before the seals: the reconstructed months
From January 5 to July 6 the ledger was weekly and reconstructed at real market prices; since July 23 it is daily, live and on-chain. The weekly table is kept below for the record — the proof of everything after July 23 is the chain of seals, not a table on this page.
Open the weekly reconstruction · Jan 5 – Jul 6, 2026
| Date | Operation | Amount | BTC bought | BTC price | BTC total |
|---|---|---|---|---|---|
| Jan 5 | Start: 20,000 into savings instruments (sUSDS); from Jan 19 a portion in zero-coupon | 20,000 | — | 93,870 | 0 |
| Jan 12 | Interest → Bitcoin | 9.57 | 0.000105 | 91,188 | 0.000105 |
| Jan 19 | Zero-coupon purchase — 4.10% fixed, maturing May 11 | 82.56 | 0.000892 | 92,560 | 0.000997 |
| Jan 26 | Interest → Bitcoin | 11.30 | 0.000128 | 88,250 | 0.001125 |
| Feb 2 | Interest → Bitcoin | 15.50 | 0.000197 | 78,667 | 0.001322 |
| Feb 9 | Interest → Bitcoin | 15.14 | 0.000216 | 70,102 | 0.001538 |
| Feb 16 | Interest → Bitcoin | 11.15 | 0.000162 | 68,858 | 0.001700 |
| Feb 23 | Interest → Bitcoin | 10.47 | 0.000162 | 64,626 | 0.001862 |
| Mar 2 | Interest → Bitcoin | 11.01 | 0.000160 | 68,832 | 0.002022 |
| Mar 9 | Interest → Bitcoin | 7.87 | 0.000115 | 68,432 | 0.002137 |
| Mar 16 | Interest → Bitcoin | 18.12 | 0.000242 | 74,886 | 0.002379 |
| Mar 23 | Interest → Bitcoin | 9.78 | 0.000138 | 70,874 | 0.002517 |
| Mar 30 | Interest → Bitcoin | 9.14 | 0.000137 | 66,737 | 0.002654 |
| Apr 6 | Interest → Bitcoin | 17.21 | 0.000250 | 68,854 | 0.002904 |
| Apr 13 | Interest → Bitcoin | 7.89 | 0.000106 | 74,446 | 0.003010 |
| Apr 20 | Interest → Bitcoin | 9.71 | 0.000128 | 75,865 | 0.003138 |
| Apr 27 | Interest → Bitcoin | 10.68 | 0.000138 | 77,364 | 0.003276 |
| May 4 | Interest → Bitcoin | 11.98 | 0.000150 | 79,852 | 0.003426 |
| May 11 | Zero-coupon redeemed, new purchase — 4.07%, maturing Aug 13 | 63.09 | 0.000772 | 81,727 | 0.004198 |
| May 18 | Interest → Bitcoin | 7.69 | 0.000100 | 76,944 | 0.004298 |
| May 25 | Interest → Bitcoin | 10.51 | 0.000136 | 77,249 | 0.004434 |
| Jun 1 | Interest → Bitcoin | 9.98 | 0.000140 | 71,314 | 0.004574 |
| Jun 8 | Interest → Bitcoin | 17.22 | 0.000273 | 63,063 | 0.004847 |
| Jun 15 | Interest → Bitcoin | 6.36 | 0.000096 | 66,277 | 0.004943 |
| Jun 22 | Interest → Bitcoin | 12.09 | 0.000189 | 63,951 | 0.005132 |
| Jun 29 | Interest → Bitcoin | 7.88 | 0.000131 | 60,163 | 0.005263 |
| Jul 6 | Interest → Bitcoin | 15.55 | 0.000243 | 64,002 | 0.005506 |
| Monthly | Basket review on the first Monday of each month: sUSDS best vs USDY, aUSDC — confirmed each time | — | — | — | — |
On-chain verification
The ledger is anchored to a multi-signature vault (Safe) on the Sepolia test blockchain. Anyone can verify, without trusting this page.
| Vault (Safe 1/1, Sepolia) | 0x7632C501E0a9e91121cB39828a0d3d2030EFcdc4 |
| Public verification | sepolia.etherscan.io → all vault transactions ↗ |
| Opening act | July 19, 2026, 16:17 — frozen rules and reconstruction results, in clear text inside the transaction data (UTF-8 decode of the Data field) |
| Daily seal | Active since July 24, 2026: every morning the SHA-256 fingerprint of ledger and journal, chained to the previous seal, is written on-chain. Rewriting yesterday would require breaking the chain: it would show. |
| Latest seal | 0xe66f9aad672047b1e2346b12946eb1820e0216b695c6f8e682f8026b7a8ee4c4 ↗ |
Three years of interest, spent on Bitcoin on day one
The discount buys the Bitcoin immediately; the treasury leg rebuilds the capital by the target date.
Today's chart
Redrawn every morning after the on-chain seal, from the public archive ↗: every day since August 18.
What happens to 10,000
You deposit 10,000. On day one it splits in two:
Eight years, simulated, net of fees
10,000 in August 2018, left alone. Real market data, net of all fees; log scale, every line doubles. Worst mark: 9,593, in December 2018.
Year-end values per 10,000
| Year end | BYA One | Treasury bills | BTC price |
|---|---|---|---|
| 2018 (Aug–Dec) | 9,653 | 10,072 | 3,692 |
| 2019 | 10,140 | 10,231 | 7,166 |
| 2020 | 12,387 | 10,248 | 28,990 |
| 2021 | 13,899 | 10,248 | 46,211 |
| 2022 | 10,691 | 10,413 | 16,530 |
| 2023 | 13,839 | 10,918 | 42,288 |
| 2024 | 20,120 | 11,438 | 93,354 |
| 2025 | 18,933 | 11,865 | 87,498 |
| Oct 21, 2026 | 18,752 | 12,182 | 84,350 |
An estimate, not a promise
| Scenario | Lowest | Ends at |
|---|---|---|
| Perfect storm: Bitcoin −60% in 90 days, rates +400 bp, 30% run (22 months) | 93 | 103 |
| Rates down to 1% in two years, Bitcoin flat (3 years) | 100 | 103 |
| Bitcoin −80% in three years, then flat (8 years) | 98 | 114 |
| Bitcoin flat for eight years | 100 | 123 |
| Bitcoin −99% in eight years | 97 | 112 |
| Bitcoin −99%, rates at zero from year two | 88 | 88 |
Simulated, not promised. Exits are always open, at the day's value minus 0.20% kept for those who stay. In development; not available to U.S. persons; not an offer.
Transparency note. Core: from January 5 to July 13, 2026, retroactive reconstruction at real market prices; from July 23, a daily ledger kept systematically, by written rules, and sealed on-chain every morning. One: live since August 18, 2026, with its own daily seal. Since October 2026 every instrument is priced at its issuer's own on-chain redemption value or NAV oracle — no aggregators. The numbers on this page come from the sealed ledgers, updated to the latest seals shown above.
The capital is simulated: no real trade has been executed. The on-chain transactions carry the text and the fingerprint of the operations, not flows of value. Simulated and past results are not indicative of future results. This page is not a public offer nor a solicitation to invest.