$NAT · the security budget
Bitcoin's block subsidy is shrinking to zero. Who pays for security then?
Drag the year toward 2140 and watch the subsidy collapse. Fees are unreliable. $NAT is one market-funded layer that can grow with demand — explore the scenarios below.
You’re looking at:
BTC subsidy
Fees (unreliable)
$NAT (market-funded)
Security gap
Year2140
The BTC subsidy halves every ~4 years — a deterministic step down to ~0 by ~2140.
$NAT subsidy
Market cap$36M
$ value
% of BTC
adds ≈$33/block of security — drag the cap to explore adoption
Assumptions
Baseline 1×
2023 spike
Fees' best case
Even maxed while usable: $0.47B/yr = 0.04% of BTC value — 22× under today. Matching the subsidy needs ~$62/tx (crisis); at 10× price, ~$620/tx.
Today
Custom
Power Law
Projection — not a forecast. Project BTC to 2140 with the Power Law — security’s share of its value falls anyway.
Per block · 2140
BTC subsidy$0
Transaction fees$1,386
$NAT (market)$40
Total / block (incl $NAT)$1,426
Bitcoin market cap—
BTC security / yr—
Security per $1 of market cap≈6×
same $1 — $NAT buys more, drawn to scale · price cancels
NAT emission held at today’s difficulty · future emissions →
Scenario — not a forecast. NAT's per-block $ is demand-driven and reflexive. Drag up to explore what larger adoption would contribute.
Bitcoin grows — its security share shrinks
Bitcoin price (Power Law)—
Increase vs today—
Bitcoin market cap—
Security spend / yr—
Security spend / yr (% of its value)
fees' usable max
0.04%/yr
22× under today · why →
Power Law (Santostasi / Burger) — a projection, not a forecast. This share is price-independent: Bitcoin’s price can soar and security’s share still falls toward zero. Even at a market cap many times the world’s wealth, security’s slice keeps shrinking.
(the red line holds fees at 0.023 BTC forever — generous: that's ~$63k per transaction at 2140 prices; capped at what users can pay, fees' share → ~0.)
So what is $NAT?
Start with the part most people miss.
Already live · since Feb 2025
Mine a Bitcoin block and you’re already earning $NAT. Automatically, to the coinbase address you already use. Nothing to install.
$NAT grows the security budget from within. Not from faith, not from fees. And its number is non-arbitrary and 100% Bitcoin-native: every block mints $NAT decoded from its own difficulty
bits, a value already in every Bitcoin header. Bitcoin’s own data sets it. No committee, no knob.×
Not a fork
Changes none of Bitcoin’s rules.
×
Not a tax
No demurrage. Takes nothing from holders.
×
Not merge-mining
No second chain. No commitment in your block.
×
Not a consensus change
Nothing to activate or vote on.
Subsidy: capped & shrinking
The block subsidy is deterministic and falling to zero. It cannot grow — it's the one revenue line guaranteed to vanish.
Fees: real but unreliable
Fee revenue is episodic and volatile — it spikes, then reverts. Miners can't budget on it, and raising it means charging users more.
NAT: market-funded, reflexive
NAT is one market-funded option — not “the solution.” Its contribution is demand-driven and reflexive: it can grow, but it isn't guaranteed.
Figures: 2026-06-26 snapshot of the baked baselines — the BTC price is fetched live on load, and the target, ratios and paradox scale with it. Subsidy 3.125 BTC/block (4th halving, block 840,000). Fees ≈ $1,359/block (24-hour average). Fee model: 3,000 tx/block, demand elasticity 1.3, usability thresholds ~$3 and ~$50 per tx; the 2023 spike ≈ $28,000/block. NAT ≈ 386,011,001 tokens ≈ $33/block at ≈ $33M mcap, decoded from the header
bits field ($NAT = s×2²⁴+c). Security benchmark ~0.5–1.5%/yr of mcap (Lyn Alden). Sources: NATpaper · mempool.space · CoinGecko · Lyn Alden. No price targets — the mcap slider is a scenario, not a forecast.Explorable · scenario tool