When multi-hop relay beats an extreme-pair arbitrage finder (SEE>>ACT)

A common trade-arbitrage heuristic picks the single most-extreme cheap->dear market pair and trades it. It has a hidden failure mode: it only fires when the cheapest and dearest markets share a DIRECT edge. In a hub-and-spoke graph the hub touches every sink so it works, but in a sparse long-diameter graph (a chain, or interstellar with only near-neighbour lanes) the global cheapest and dearest are NOT directly connected, so the finder fixates on the un-connectable pair and opens NOTHING (delivers 0 to the far market). A multi-hop relay (forward goods one hop toward the highest discounted reservation value) threads goods across regardless. So the relay mechanism is load-bearing exactly when SEE >> ACT: you can see a distant lucrative market but no single lane spans the distance — frontier chains, today-physics interstellar (light-speed comms, sub-light freight), and high-risk/fast-congesting lanes (where a direct long haul is unaffordable or saturates, and high per-hop risk strands goods midway into a realistic persistent frontier spread). Validated with a finder-vs-relay experiment on chain vs hub topologies.