# VIOLET Research TODO — Why does the IRP pick stablecoins when unguarded?

**Status:** Research TODO (logged 2026-06-14). Low priority, high curiosity. Not blocking.

## Observation

The VIOLET shadow soak, running BLUE's muted-IRP gold config (`min_irp_alignment=0.0`)
WITHOUT BLUE's stablecoin exclusion gate, repeatedly ranked **USDCUSDT** top and would
have shorted it at full conviction (9.0). BLUE hardcodes these out
(`_STABLECOIN_SYMBOLS`, nautilus_event_trader.py:24/3906 — "must never be traded"), and
VIOLET now replicates that (commit V3.1). So in production it's correctly excluded.

## The question

**Why does the IRP ranker select stablecoins when unguarded — and is the exclusion
leaving a real (small, desirable-to-forgo) edge on the table?**

Two hypotheses:
1. **Noise/artifact.** Stablecoin price series are near-flat; the IRP efficiency/ARS
   metric may divide by a tiny denominator (low realized vol), inflating the score on
   essentially flat micro-movements → a spurious "clean signal." If so, exclusion is pure
   correctness (avoids dividing-by-near-zero noise).
2. **Real micro-edge, deliberately self-limited.** Stablecoin depeg oscillations
   (USDC/USDT wobbling around \$1) are mean-reverting and genuinely tradeable at tiny
   size — the IRP may be detecting a real, low-volatility, low-risk signal. BLUE's
   exclusion would then be forgoing a small but real edge BY DESIGN (correctly — pegged
   assets carry depeg tail risk, poor borrow, regulatory/operational hazards that dwarf
   the micro-edge; not worth it).

## How to settle it (when researched)

- Backtest the EXCLUDED stablecoin picks as if traded (small size): realized PnL,
  Sharpe, max depeg drawdown, borrow/funding cost. Does the micro-edge survive costs +
  the depeg tail?
- Inspect the IRP ARS/efficiency computation on flat series (rank_assets_irp_nb): is the
  high score a denominator artifact (hypothesis 1) or a real efficiency signal (2)?
- Cross-check against the dual-leverage/conviction the sizer assigns (it gave conviction
  9 on USDC vel_div −0.0585 — is that vel_div itself an artifact of a flat series?).

## Why it matters (mildly)

If hypothesis 2 holds, it informs whether a *separate, tiny-size, depeg-aware*
stablecoin strategy could be a future color — orthogonal to BLUE's directional short
edge. If hypothesis 1, it's just confirmation the exclusion is correctness. Either way,
VIOLET keeps the exclusion (follow BLUE). See
[[blue_margin_envelope_study]], [[violet_v3_alpha_doctrine]] (#12 follow-BLUE).