Dollar-Cycle EM Relative Trade: hold EEM vs SPY dollar-neutral in the direction of the euro ETF's 20-session trend (long EEM / short SPY when FXE is rising = dollar weakening, the reverse when FXE is falling), weekly decision, next-open fills (USEQ 1-DAY, long-short, FXE signal-only)

Original Research Lead hypothesis. It is a dollar-neutral, two-leg US-listed ETF spread driven by an EXTERNAL signal, the US dollar's trend, measured by the euro-currency ETF FXE. Mechanism, with instruments removed: a weakening dollar loosens financial conditions for emerging markets and a strengthening dollar tightens them. EM corporates and sovereigns carry large dollar-denominated debt, cross-border bank lending and portfolio flows into EM follow the dollar with a lag, and EM equity returns in USD also carry currency translation, which trends (currency momentum). This is the 'dollar as a global risk factor' channel: Bruno and Shin (2015), and Avdjiev, Bruno, Koch and Shin (2019, IMF Economic Review). So EM equities should outperform US equities for weeks after a dollar decline and underperform after a dollar rally. EUR/USD is used as the dollar proxy because the euro is about 58% of DXY, and FXE trades on the same venue and session as the traded legs, so the signal is point-in-time with no publication lag. INSTRUMENTS: EEM.USEQ (iShares MSCI Emerging Markets) and SPY.USEQ are traded. FXE.USEQ (Invesco CurrencyShares Euro Trust) is a signal-only leg and is never traded. All three have 1-DAY bars in the catalog; the joint history starts at FXE's 2005-12-12 listing, about 20.8 years. Primary instrument: EEM.USEQ. extra_instruments: SPY.USEQ, FXE.USEQ. RULE: on the LAST trading session of each week (use the session helpers, never a hard-coded weekday, so holiday weeks work), compute s = ln(FXE_close_t / FXE_close_{t-lookback}), with lookback = 20 sessions by default. If s > +deadband, target LONG EEM / SHORT SPY. If s < -deadband, target LONG SPY / SHORT EEM. Inside the deadband, keep the current book. With the default deadband of 0 the book is always in one state after warm-up. Orders are decided at that session's close and fill at the next session's open, which is the platform's supported next_open_fill on USEQ. Rebalance only when the target state flips. Within a state, no weekly re-sizing, so turnover stays low. SIZING / RISK CONTROL route (b): signal exit plus capped sizing. Each leg is 50% of current equity at entry (whole shares, floor), so gross is about 100% and net about 0. No position exceeds 50% of equity, inside 2x Reg-T margin. The exit is the signal flip. There is no stop. Pre-study volatility of this book is about 8% a year, well inside the conservative profile's 60% band. Leverage is 1.0x gross. RESEARCH LEAD PRE-STUDY (pandas, close-to-close, weekly decision at the week's last session, held from the next session, no costs, 2006-2026). It was used to choose this idea over three others, not as acceptance evidence. Four other macro-impulse spreads were screened and DISCARDED in the same pass: breakeven-inflation momentum to XLE+XLB vs XLU+XLP (Sharpe -0.31 to 0.03), real-yield momentum to QQQ vs XLE+XLF (negative), 2s10s steepening to XLF vs XLU (about 0.1), and VIX change to IWM vs SPY (about 0). A cross-country term-spread rotation was also discarded (t of about 0). The FXE 20-session rule gives Sharpe 0.49 on the full-notional spread from 2006 (15 of 21 years positive) and 0.79 after 2015. The lookback neighbourhood is positive throughout: FXE 15/20/30/40 sessions give 0.20/0.49/0.19/0.27, and FRED EUR/USD gives 0.15 to 0.48 over 15-60 sessions. Since 2008 there are 225 position episodes (111 long-EEM), with a mean spread return of +0.70% per episode before costs and a 56% win rate. At 50/50 notional, annual volatility is 8.1% and max drawdown 19.0%. INCREMENTAL-INFORMATION CONTROL (lesson L217, pre-registered): the same instruments, clock and lookback, signed by the EEM/SPY spread's OWN 20-session momentum instead of FXE, give Sharpe 0.16 over the full history and -0.37 after 2015 (10- and 40-session versions are about 0 or negative). The FXE signal also stays positive (0.29) on the weeks when it DISAGREES with the spread's own momentum. The external dollar signal therefore carries information beyond spread momentum. The developer should report this control beside the result: require_fx_signal=false switches the sign source to the spread's own momentum, as a shadow comparison only. DISTINCT EVIDENCE UNITS (lesson L238): about 1,080 weekly decision dates and about 240 position episodes (about 480 leg trades) over 2006-2026. The two legs of an episode are one bet, so the episode count is the honest sample. That is far above the roughly 30 events lesson L237 asks for, and every leg has bars over the whole span. FEE ARITHMETIC: USEQ has zero commission. Spread plus impact is about 0.02-0.05% round trip per leg, so about 0.1% of one-leg notional per episode for both legs. The expected gross capture is about +0.70% of spread per episode, or about +0.35% per leg, which is over 3x the cost. The analyst floor on USEQ is about 0.05% per trade. DIVERSIFICATION: USEQ is not a crypto venue and adds a macro-FX driver that no deployed strategy uses (the promoted NFCI sector spread uses credit and financial conditions, not the dollar). It is long-short and dollar-neutral (long-short is 24% of the corpus) and is neither BTC nor a momentum/NR7/shock-absorption clone. The abandoned 'Month-End FX Hedge-Rebalancing FXE' hypothesis traded FXE itself on a month-end calendar. This hypothesis uses FXE only as information about the dollar cycle and trades EM vs US equities on its trend.