BTC Volatility-Targeted Time-Series Momentum (Single-Instrument USD-M, Long-Short, Daily, Constant-Volatility Exposure Scaling, Capital-Capped)

A LONG-SHORT, SINGLE-INSTRUMENT TIME-SERIES MOMENTUM strategy on BTCUSDT.BINANCE USD-M perpetual futures (daily bars) implemented in its CANONICAL academic form (Moskowitz-Ooi-Pedersen 2012): hold LONG when BTC's own trend is up and SHORT when down, with the position CONTINUOUSLY SCALED to a CONSTANT TARGET VOLATILITY. This is deliberately NOT what the analyst told me to stop generating: it is NOT a momentum-BASKET variant (it is single-instrument), and it is NOT a weaker proxy of the return-momentum factor -- it is the STRONGEST, canonical form (trailing-return trend) with the documented constant-volatility overlay that DEFINES time-series momentum and materially improves its Sharpe and drawdown. The factory's existing simple BtcTimeSeriesMomentum is the sign-only version; this adds the volatility-targeting that is the academic construction's actual definition and its largest robust Sharpe-enhancer. EVERY design choice respects this session's binding lessons: (1) MOMENTUM direction -- the only validated edge (cross-sectional 0.97 / absolute 1.36 / dual 1.61 baskets all positive and in optimization; every fade/reversion anti-predictive). (2) BTC -- the most robust, lowest-noise asset; plain TSM already works on BTC/ETH/SOL in the portfolio, so survival is high (this is NOT a fragile alt pattern-transfer like the ADA/XRP failures). (3) LONG-SHORT -- net-SHORT in BTC bear trends delivers REAL crash protection, unlike the abandoned long-only dual-momentum cash-gate rotation whose flat-only gate failed to protect in the 2022 bear (-42.8%). (4) CAPITAL-CAPPED SIZING -- the recurring engine bug (>100% notional, +200-300% impossible single days) is caused by sizing against an unrealized-PnL-inflated equity base during parabolic holds; this sizes against a STABLE realized-equity base and hard-caps gross exposure, so the inflation cannot occur. (5) FUTURES -- the analyst's prescribed venue for vol-targeting (clean discrete trackable position-size changes; no spot CASH accounting bug). (6) PURE OHLCV -- trend and vol from price; immune to funding-data-end-2024 and the 0-for-8 supplementary-stream kills. Intentionally minimal: 3 tunables (trend_lookback, target_vol, vol_lookback).