A LONG-ONLY spot BTC accumulation strategy on BINANCE_SPOT whose entry is gated not by a price pattern but by a crypto-native STRUCTURAL deleveraging event: a sharp collapse in perpetual open interest combined with a funding-rate flip to negative, coincident with a price drawdown. This is deliberately a DIFFERENT FAMILY from the abandoned Deribit calendar/term-structure options line (which died verification_loop across 3 iterations) — different instrument class (spot, not options), different mechanism (structural mean-reversion off a forced-liquidation exhaustion signal, not vol-term-structure carry), different data (open interest + funding, not greeks/IV), and a different venue in the portfolio's highest-survival, most under-represented sleeve (BINANCE_SPOT at ~6% vs the ≥15% quota). The thesis: violent cross-market deleveraging (cascading long liquidations) mechanically compresses open interest and drives perp funding negative as shorts pile in at the lows; once forced sellers are exhausted, spot has no structural seller left and mean-reverts several percent over the following days. We buy that exhaustion and hold for the reversion, not a directional forecast. Turnover is low (only genuine washout events fire — a handful per year), so the 0.20% spot round-trip is negligible against multi-percent target moves. It avoids the momentum-confluence graveyard (L38), the major→alt signal-transfer and pair-ratio families (L40), Hyperliquid (L39), the intraday 4H-price-gate-with-a-feed template (L46 — this is a multi-day structural event, not an intrabar gate), and the delta-neutral funding-carry sample/fee traps.