$NAT · Security Budget Tools

Bitcoin pays less for its security every four years, whatever the price.

1Bitcoin Security Intensity (BSI)
Bitcoin pays 0.82% of its value a year to the miners who secure it.
block subsidy 0.819%fees 0.006%, the only part that doesn’t halve
Same answer at any price (paid to miners ÷ market cap)
Why the price doesn’t matter
165,543BTC paid per year×P 20,077,994BTC in existence×P cancels
=165,543÷20,077,994=0.82%
2The schedule
It halves every four years. Price rose each time; the budget halved anyway.
below every published floor30%10%3%0.3%0.1%2%Hasu, 20201.5%McAvity, 20231%The NAT paper · btcsecuritybudget.com0.7%Gold0.5%Alden’s floor2012201620202024202820322036today 0.82%0.42%0.21%0.11%33%budget −60%price ×19.9budget −51%price ×2.0budget −48%price ×2.3budget −50%price ×2.5budget −50%price ?30%10%3%0.3%0.1%2%1.5%1%0.7%0.5%2012202020282036today 0.82%0.42%0.21%33%−60%×19.9−51%×2.0−48%×2.3−50%×2.5−50%?
Under each halving: the budget’s change and the price’s change, 200 days either side. The price rose every time.
Benchmarks: 2% Hasu, 2020 · 1.5% McAvity, 2023 · 1% The NAT paper · btcsecuritybudget.com · 0.7% Gold · 0.5% Alden’s floor
3The only fix
0.42%after the 2028 halvingbelow all six published benchmarks
33×today’s fees, to get back to 1%a higher price can’t close the gap; only fees can
FIGURES VERIFIED · Checked 31 Aug 2026 · Next halving ~Apr 2028 · not a price feed

The scale — and what it would take to get back inside it

Every published benchmark is a zone; the lit one is where Bitcoin currently stands. Move the halving year and the fee multiple — the needle moves with them. Price is deliberately absent: it cancels out of the ratio.

today 0.82%
0.82%
below every floor<0.5%
inside Alden0.5–1%
healthy · NAT target1–1.5%
above the published range>1.5%
← “a different protocol”
0.5% Alden floor
0.7% gold
1% NAT paper
1.5% ceiling
2% Hasu
Where on the schedule
Fees, as a multiple of today
1×today’s fee revenue
$NAT — the second subsidy
$NAT market cap, as a share of Bitcoin’s 2.00%

Who published what

Every row is read against the scenario you set above: the marker is Bitcoin’s current position on that source’s own scale. Distance is the fee multiple that would lift Bitcoin to that source’s floor; click it and the slider goes there. Source opens the verbatim quote — and, under it, the two things that would close the gap to that specific source: fees, or $NAT. These are not our numbers; the bridge to $NAT is ours alone.

6 on BSI · 2 on attack cost · every row states its source and whether it is verified
WhoPublished level (0–2.2% of cap)Levelvs. scenarioDistanceSource
Lyn Alden2021·of market cap
0.5–1.5%
“something more like 0.5% to 1.5% of market capitalization spent on security would probably be appropriate.”
Read the source ↗On The Wall▶ The videos
Hasumeasured 2020·not a target
2%
“One could say Bitcoin’s security budget is 2% of its network value.” — a measurement of 2020, not a level he prescribed. It is on this page as a reading Bitcoin has already fallen below, never as a bar to clear.
Hear it at 3:04 ↗On The Wall
James McAvity18 Oct 2023·The Mining Pod
~1.5%
“The metric that I like to look at is what is mining revenue versus the total market cap of Bitcoin. And right now it’s around one and a half percent. You wanted to stay in a healthy range there.” — the level he said it should stay at, in 2023. Below 0.2% he called it “a different protocol” (further down this table).
▶ Watch him say it
btcsecuritybudget.comsite FAQ·its Settings ship at 0.25%
1%
“The three memes are in a ‘good’ state if … the relative miner revenue is greater than 1%.” — the site’s own FAQ, defining its secure state. A documented threshold, not an argued case. Its Settings dialog ships at 0.25% and Reset returns 0.25%, so the page marks Bitcoin secure against a line four times below the one its text describes. Its model reads 0.82% for 2026 at default settings, the same figure as this page.
Read the source ↗
The NAT paperp.3 / p.18·OUR OWN target
>1%
“Elevate BSI above 1%” — the level the proposal is engineered to reach. It sits inside every band above.
Read the paper ↗The explorable →
GoldSam Wouters 2023·comparator, not a floor
~0.7%
“I don’t feel confident enough to say like that is a good healthy approach to look at it. But if you do take that approach of the 0.7 percent — which is, from what I could tell, sort of what people are spending to secure their gold every year — if you take that for Bitcoin, then you’d get to a security budget currently of about 2.2 billion dollars. So yeah, I’m just not sure that analogy works.” A comparator he raised and doubted in the same breath — not a floor. One more halving puts Bitcoin under it.
Hear it at 31:20 ↗▶ The videos
“A different protocol”McAvity·floor
0.1–0.2%
“If that drops down to say 20 basis points, 10 basis points, maybe even lower … It’s just a different system. It’s a different protocol.” — the schedule reaches it in three more halvings.
▶ Watch him say it
Two Ethereum critics, counting what an attack costs rather than what Bitcoin pays, put the floor at 0.1% — inside the 0.1–0.2% a Bitcoin miner called “a different protocol”. different basis ▾
Grant Hummer2025·Etherealize co-founder
not on this axis — see below
0.1%
the floorattack “virtually certain”
“Respectfully, BTC is completely screwed because of its security budget. It would only cost $8B to 51% attack BTC today. When this gets down to $2B (AKA, BTC’s security market cap becomes 0.1% of its asset market cap), a 51% attack is virtually certain to happen. This will become blindingly obvious over the next decade. ETH is the only truly decentralized crypto-asset that can become the internet’s SoV Schelling point.”
Justin Drake2025·Ethereum Foundation
not on this axis — see below
$10B
May 2025“a rich nation state”
A 51% attack on Bitcoin would be “much cheaper” than on Ethereum, costing “on the order of $10 billion”. “A rich nation state can probably pull it off.”
Their ruler — one-off cost to attack ÷ market cap axis 0 → 0.6% · a capital stock, not an annual flow — never summed with BSI
0.1%Hummer · “virtually certain” ~0.4%$8B · May 2025 ~0.5%$10B · May 2025
0.1% and the $8B / $10B attack costs are quoted. The ~0.4% and ~0.5% positions are derived — their dollar figures over the ~$2T market cap their own arguments assume. We show the arithmetic rather than quoting a ratio neither man stated.
Why they are here at all. Opposite incentives, different rulers, the same floor. Neither is a friendly witness — Hummer’s same post argues ETH should be the store-of-value Schelling point instead, and we quote that sentence rather than cutting it. That is the point: the floor is agreed by people who agree on nothing else.