One Percent, Both Ways

A 1% slice can cost a little, or add anywhere from a little to a lot. The calculator shows both, and the return it uses is your assumption, not ours.

A Decade Rhymes looked backward at ten years that already happened. This page looks forward, and the honest thing about looking forward is that nobody knows. So it doesn't pretend to. It takes a pile, puts 99% in traditional investments and 1% in Bitcoin, and shows what happens under whatever assumptions you give it.

Everything on this page is before inflation, the 7% included, because Bitcoin's history is only measured that way. Keep both returns on the same footing and the comparison stays fair.^M

Four buttons: two edges and two stretches of history

The buttons set only Bitcoin's return. With the defaults ($100,000, ten years, traditional investments growing 7% a year before inflation), the all-traditional pile ends at $196,715.^M

• Goes to zero. The mix ends at $194,748. The mix gives up 2.0% of the gain.
• Flat. Bitcoin goes nowhere, and the mix gives up 1.0%.
• Its last 5 years (the default). 24.8% a year, 2021–2025, before inflation. The mix ends at $203,913, and the 1% adds 7.4% to the gain.¹
• Its last 10 years. 70.2% a year, 2016–2025, before inflation. The mix ends at $398,732, and the 1% adds 208.9% to the gain.¹

History, not a forecast. The page opens on the shorter, calmer window on purpose. The 10-year figure leans heavily on the 2016–2017 run-up, and as of Oct 8, 2026, Bitcoin's price sat below its Dec 31, 2025 close, so a window ending today would come out lower than either one.¹ The cost has a floor: the slice itself. The gain has no fixed ceiling, which also means there's no number to count on.

Two numbers that sound alike

The big number is what 1% adds: how much bigger the mix's gain is than the all-traditional gain. It can go past 100%, because a fast-growing slice can more than double the gain. Underneath it, smaller, is Bitcoin's share of the gain: how much of the mix's own gain came from the Bitcoin slice. That one can't pass 100%. At the 5-year default it's 7.9%; at the 10-year pace it's 67.9%.^M Same scenario, two honest ways to say it.

The break-even line

Here's the plain rule: the 1% only helps if Bitcoin grows faster than the traditional 99%. Set Bitcoin's return equal to the traditional return and the mix lands exactly on the all-traditional result. The chart draws that line and moves it when you move the traditional return.

The default is history, and it's still a guess

The default is Bitcoin's own last 5 years, before inflation: 24.8% a year, compounded, from the Dec 31, 2020 close to the Dec 31, 2025 close.¹ Past years don't promise future ones, so the input stays labeled "your assumption", and you can set it anywhere.

That 24.8% is the median yearly growth: the middle path, not the mean. For something this jumpy the gap is big. At 80% volatility, a 24.8% median works out to an average (mean) yearly return of about 71.9%, because a few huge years pull the mean way up while the typical path stays near the middle.^M We show the median on purpose.

The 80% volatility matches how much Bitcoin's yearly returns swung over the last five years. Over ten years the swing was wider, 115%. Measured from daily prices instead, it's lower, 59% to 68%, so the number depends on how you measure it; this page means yearly.¹ Even in the decade it grew about 204-fold, it fell 84% from a peak once and 77% another time.¹ Anyone holding it lived through both.

What some Bitcoin holders project, in their own words

Some well-known Bitcoin holders project far more than either window. They're quoted here so you can see the claim and who's making it, not as a consensus or as our view.

Michael Saylor put it plainly in July 2024: "$13M is the #Bitcoin Base Case."² The model behind it, Bitcoin24, runs from 2024 to 2045; its base case works out to about 28.9% a year, before inflation, on a path that starts fast and slows down.^{3 4} The model itself notes that it "does not model Bitcoin's volatility."⁴ ARK Invest's 2030 cases are "bear, base, and bull cases of ~$300,000, ~$710,000, and ~$1.5 million per bitcoin"; the base case works out to about 40% a year from the end of 2024 (our arithmetic), and ARK labels its own forecasts "HYPOTHETICAL AND HIGHLY SPECULATIVE."⁵

Both have a stake. Saylor's company, Strategy, held about 848,000 bitcoin as of Oct 8, 2026, and ARK co-brands a bitcoin ETF (ARKB, sponsored by 21Shares) and manages digital-asset funds.⁶ That's why neither projection is a button on this page. The evidence comes first; their views are theirs.

The chance of zero is our assumption

The input labeled "Chance bitcoin goes to zero" starts at 10%. That's our assumption, not a forecast. No study pins this down, and we looked. Set it anywhere from 0% to 50%.^M

Here's how it works. In each of the 10,000 lives the page runs, there's one draw: with the chance you set, Bitcoin goes to zero at some point during the period, in a year picked at random. From that year on, the Bitcoin slice is worth $0 and stays there. It's one event over the whole period, not a risk that resets every year.^M The results further down count those lives in, and the page says what share of lives hit zero.

We kept this to Bitcoin on purpose. Studies of how often crypto coins fail cover thousands of other, mostly small coins, so they don't tell us anything about Bitcoin, and we don't use them here.

What markets have priced, for background

There are a few Bitcoin-only numbers on the record, and they're a different kind of number. A 2018 Yale study by Yukun Liu and Aleh Tsyvinski, as CNBC reported it, put "the current implied daily disaster probability" at "about 0.4 percent for Bitcoin."⁷ A paper that read one day's Bitcoin option prices got 0.87% and 2.50%.⁸ Both are market-implied: prices traders charge for short-term risk, over a day or a single option's life. They aren't real-world odds over years, and they can't be multiplied out into a yearly figure. Critics like Nassim Taleb argue Bitcoin's value heads to zero, but they don't give a probability.⁹

The range, not just the middle

Because the future isn't one line, the page also runs 10,000 possible paths with your settings, including the lives where Bitcoin hits zero. At the defaults, the typical (median) outcome for the mix is $201,212, the 10th percentile is $194,762, the 90th is $383,210, and the mix beats all-traditional in 65.4% of the paths. In 9.46% of these simulated lives, bitcoin went to $0 and stayed there.^M Set the chance of zero to 0% and the typical outcome rises to $203,766, with the mix ahead in 72.6% of the paths.^M

How this differs from the history page

A Decade Rhymes trims its slice back every Dec 31 (rebalanced once a year). This page doesn't: both piles are put in once and left alone, so a slice that grows gets bigger. And the traditional 99% grows at a steady rate with no ups and downs, so the only moving part is the Bitcoin slice.^M

What this is not

This isn't a forecast for Bitcoin, and it isn't a suggestion to own any. The defaults are history, the quoted projections belong to the people who made them, and every return on the page is an assumption the reader sets. What it shows is the arithmetic of a small slice: what it can cost, what it can add, and where the line between them sits. Education, not advice.

Now look back: A Decade Rhymes. The same small slice, rebalanced through ten years that already happened.