{
  "version": "composition-controls-v1",
  "stage": "Second exploratory block declared after observing defensive overlay results. Not a pre-registered holdout. No trend parameter changes.",
  "purpose": "Separate asset composition effects from trend timing. Keep equities, long Treasuries, gold and T-bills at 25% each; no extra leverage.",
  "variants": {
    "US25": {
      "SPY": 0.25,
      "TLT": 0.25,
      "GLD": 0.25,
      "BIL": 0.25
    },
    "US-Nasdaq-mix25": {
      "SPY": 0.125,
      "QQQ": 0.125,
      "TLT": 0.25,
      "GLD": 0.25,
      "BIL": 0.25
    },
    "Global25": {
      "VT": 0.25,
      "TLT": 0.25,
      "GLD": 0.25,
      "BIL": 0.25
    }
  },
  "rebalance": "Monthly first equity trading close",
  "mixed_trend": "Apply the SAME 10 completed month moving average separately to SPY/QQQ/TLT/GLD; off sleeve goes to BIL without increasing others. Same lag and execution assumptions.",
  "comparison": "US versus mixed equities on original 2007-05-30 cutoff window; all three compositions on identical VT inception window. Do not directly rank mismatched periods.",
  "cost_bps": 5,
  "limitations": [
    "Nasdaq overlaps US market and concentrates growth/technology within the equity sleeve; not independent asset-class diversification",
    "No 2000-2002 common four-asset ETF history, retrospective winner selection possible",
    "All variants exploratory and require separate robustness/forward evaluation before promotion"
  ]
}