$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.

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 layer
Without NAT
With NAT
NAT market cap$36M
Scenario — not a forecast. NAT's per-block $ is demand-driven and reflexive. Drag up to explore what larger adoption would contribute.
Fees
Baseline
Congestion spike
Fees swing wildly with mempool activity — episodic, never guaranteed.
Bitcoin price
Today (fixed)
Power Law → 2140
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 security budget$1,426
2.8%
of the security budget is NAT
Bitcoin grows — its security share shrinks
Bitcoin price (Power Law)—
Increase vs today—
Security spend / yr (% of its value)—
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.

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 — verify live before publishing.  Subsidy 3.125 BTC/block (4th halving, block 840,000) × BTC ≈ $60k. Fees ≈ $1,359/block (24-hour average, mid-2026). 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