Bitcoin Universe · Model 10

The blockspace market

Why fees rise and fall. Payments wait in a reservoir sorted by how much they pay per virtual byte; a miner packs the next block from the top until it is full.

Simulated mempool and miner policy

Congestion Miner ignores packages (naive, for comparison)

Your payment

Size Fee rate

Replace at Child pays

Next block

Your transactions, the next-block selection and the fee-rate cutoff Simulated mempool, arrivals and miner policy

The block is a scale model of 6,000 vB; a real block holds 4,000,000 weight units, about 1,000,000 vB. The selection policy (ancestor-package fee rate) and the replacement rules are simplified simulations of common node and miner behaviour; real mempools are node-local, policies vary by software and version, and miners may also include transactions for other reasons. Waiting estimates assume nothing else changes.