In physics, energy cannot be destroyed – it only changes form. Transaction ordering works the same way: wherever a ledger executes transactions against valuable shared state, the order of execution carries economic value, and that value is conserved across every architecture we know. Ethereum auctions it, Canton hides it behind contracts and NDAs, traditional finance carried it for a century as payment for order flow and last look, Hyperliquid burns it. Continuing our Block Building series, we trace this conservation of ordering value across four regimes and show why the real question is never "MEV or no MEV" but whether the price of ordering is public or hidden.

Since 2024, validators have earned $1.36B in execution-layer rewards – and builders retained $404M in surplus. Where does that edge come from? Continuing our Block Building series, we trace it to exclusive orderflow relationships: why Titan builds half of all blocks but captures 80-85% of builder surplus, how the beaverbuild-to-BuilderNet transition reshuffled the market's most valuable flow, and why block building is a contest of bilateral, contestable relationships rather than platform lock-in.

Who actually pays for priority on Ethereum? Continuing our Block Building series, with the first half of a two-part deep dive into the state of Ethereum block building since 2024: The demand side.

This is a high-level explainer of the Ethereum transaction supply chain and market structure. It aims to set the stage for readers unfamiliar with these topics before using deep on-chain data to quantify the transaction supply chain and its key players in our forthcoming research series. See also the thematically structured glossary below.