grand-exchange-live: the stepped market engine, and the turn budget binds

Arena's first interactive environment, as its own wheel beside grand-exchange so
the one-shot scores stay comparable rather than conflated. One basket of orders
becomes a loop: quote, see fills and the next tick, re-quote, with inventory,
open orders and cash carrying between turns.

The engine and its measurement only. No taskset, no config, no probe row — the
spec's constants were derived from a throwaway engine and did not reconcile
(impatient computed to 0.612 against a reported 0.623), so every constant here
is chosen from a ladder re-measured in the code that ships.

House rule 4 asks whether the turn budget binds. It does: exhaustive 0.631 vs
oracle 1.000, gap 0.369, stdev 0.054 over five blocks, worst block 0.316, and
0.354-0.405 at four further seed bases. That is 18x the proposed margin and it
clears the 0.25 quantum of the binary gate outright, so the comparison is not a
cliff. The saturation worry does not fire: per-basket clipping is not clipping
the mean, so exhaustive averages 0.849 on profit_ratio rather than 1.000.

The first draft's gap was FAKE — a clean-looking 0.152 produced by an under-tuned
denominator whose every-look sibling earned 22% more gp while scoring below it.
It was caught only by sweeping the reference's own family. Nothing that scores
below the oracle may earn more than it; that check belongs in every interactive
environment that follows this one.

freeze is derived from market.seed inside build_market so viability and scoring
see one value, roc is on peak rather than average capital employed, and the
reference is cached per seed so scoring never re-simulates the played episode.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

This commit is contained in:

karti

2026-08-21 15:55:12 -07:00

co-authored by

Claude Opus 5

parent 8fe348ca82

commit 00d21025ff

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				[project]

				name = "grand-exchange-live"

				version = "0.1.0"

				description = "grand-exchange-live — quote, watch the tape, re-quote, over a turn budget."

				requires-python = ">=3.11"

				dependencies = ["verifiers"]

				[build-system]

				requires = ["hatchling"]

				build-backend = "hatchling.build"

				[tool.hatch.build.targets.wheel]

				packages = ["grand_exchange_live"]