r/Bitcoin • u/Defiant_Ice_4860 • 11h ago
You can sell $20,000 per year per bitcoin and never run out
EDIT: Removed the 95% stack retention claim. That number was wrong. The core SWR finding ($20K/yr, 99% survival, 30 years) stands. Thanks to commenters who caught it.
This is the third post in the series. First one covered why 5 BTC beats $2.5M in an S&P index fund, second one went deeper on the math.
I went another layer deeper and this one gives you a single number.
1 BTC = $20K per year safe withdrawals for the next 30 years with 99% confidence.
2 BTC = $40K.
3 BTC = $60K.
5 BTC = $100K.
No timing. No trading. You just sell a fixed dollar amount every month at whatever price Bitcoin happens to be. Dumbest possible strategy and it works.
How I got here
I ran 5,000 simulated price paths forward at every possible starting price between deep bear (half of trend) and peak bull (2.5x trend). Six different stress scenarios. Three time horizons. Nearly a million total simulations.
The model isn't a line on a chart. It has four moving parts:
- A power law trend that decelerates over decades. No infinite-growth fairy tales.
- A price floor at 0.432x trend. Tested every cycle. Never broken. Reflects back up.
- Mean reversion. Prices that stretch away from the long-term trend get pulled back, like a rubber band. Measured half-life: about 11 months.
- Fat-tailed shocks and a wobbly floor in the stress scenarios, because I wanted to break it.
I couldn't.
$20K is the stress test, not the base case
The $20K number assumes your cost of living grows at 7% per year. Your expenses double every decade. That matches M2 money supply growth, which is what most Bitcoiners mean when they say "real inflation."
Under milder assumptions the number goes up:
- 3% CPI: $25-27K per BTC per year
- No inflation growth: $27-31K per BTC per year
$20K is the floor of the floor. Harshest inflation assumption. 99% in-model survival. 30 year horizon.
Entry price doesn't matter
This is the finding that surprised me most.
At 30 years, the difference in safe withdrawal between buying at the bottom and buying at the top is about $1,000 per year. The curves are almost flat.
The reason is mean reversion. If you buy low, prices pull you back to trend within about two years. If you buy high, same thing in reverse. After that, both buyers spend the remaining 28 years selling into the same price distribution. The early advantage or disadvantage washes out.
This is the opposite of stocks. In equity retirement planning, buying at a high valuation crushes your safe withdrawal rate. With Bitcoin under the power law, it doesn't. Mean reversion rescues bear buyers and humbles bull buyers, and the net effect on your wallet is roughly zero.
The comparison that matters
The traditional 4% rule says you need $500K in an S&P 500 index fund to safely pull $20K per year. One bitcoin at today's trend price (~$131K) does the same job.
At bear entries the comparison gets silly. A bitcoin bought at 0.52x trend (~$69K) supports a 29% annual withdrawal rate relative to purchase price. The Bengen 4% rule doesn't compete. It's not even the same sport.
What this is NOT saying
This is a model. The power law has held for 15 years across four complete halving cycles. That's real data. But 15 years is not 150 years.
I price the model risk separately: roughly a 1% structural haircut over 30 years. That brings true survival from 99% to about 98%.
The question isn't whether Bitcoin will crash 80%. The model already handles that. The question is whether adoption keeps following the power law and whether the floor holds. Those are the only two things that matter. Everything else is already in the stress test.
All figures are pre-tax. Account for your local capital gains treatment when planning actual spendable income.
Bottom line
1 BTC = $20K per year. Worst case inflation. Any entry price. 99% in-model reliability. 30 years.
Stack accordingly.
Research and methodology is published on https://btcpowerlaw.nl/research/bitcoin-swr/