[C] Atlas Message — RLUSD Exposure Headroom Ruling

To: Atlas CC: Katja (Captain) From: Vesper Date: 2026-04-17

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Context

Cleanup branch is done. FLAG-034, max_inventory_usd retirement, FLAG-033, FLAG-028 — all landed with tests. Ready to merge.

One blocker before the next session: Orion's RLUSD exposure trace found a tripwire.

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The Problem

max_rlusd_exposure = 120.0 is a hard HALT (risk_engine.py:96, strict >). Not a gate on quoting — a session-ending kill.

Current live state: - RLUSD balance: ~97.6 - Headroom: ~22.4 RLUSD - base_size_rlusd = 15

What happens when fills resume: - 1 SELL fill (base size): 97.6 → 112.6. OK, 7.4 RLUSD under cap. - 2 SELL fills same session: 97.6 → 127.6. HALT. - 1 SELL fill + size-skew (up to 19.5 RLUSD): 97.6 → 117.1. 2.9 RLUSD from cap.

Running the diagnostic session at current config means the engine very likely halts on the second SELL fill. That would contaminate the diagnostic run before we get useful data.

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The Question

Orion recommends raising max_rlusd_exposure from 120 to 140 or 150.

At 150: - Headroom: ~52 RLUSD - Comfortably covers 3 SELL fills at base size (97.6 + 45 = 142.6, still under cap) - With size-skew: 97.6 + 3 × 19.5 = 156.1 — would still breach at 3 fills in same session, but that's an extreme inventory drift scenario

At 140: - Headroom: ~42 RLUSD - Covers 2 SELL fills cleanly (97.6 + 30 = 127.6, under cap) - Third SELL fill would breach (127.6 + 15 = 142.6 — under 140? Actually: 97.6 + 45 = 142.6 > 140 → HALT on 3rd fill)

My recommendation: 150. Portfolio is ~$200, RLUSD exposure cap should be sized proportionally. At ~$200 portfolio, 150 RLUSD cap = 75% of portfolio in RLUSD — reasonable ceiling for a market maker.

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The Ask

Rule on max_rlusd_exposure. If approved, Katja commits the config change before merge + next session.

This is the last open item before the diagnostic run.

— Vesper