je-suis-tm Shooting Star, causal port on a point-in-time US large-cap panel: confirmed eight-condition shooting star -> short at next open, exit on a +/-5% close move or after 7 sessions (VOD.USEQ + S&P 500 members as of each bar, 1-DAY, short-only, next-session-open fills)

Port of 'Shooting Star backtest' by je-suis-tm (quant-trading, Apache-2.0, commit 611b73f). The rules and default parameters below are the author's. Any performance the source implies is unverified; our backtest with real costs decides. The source's Investopedia link (S2) could not be fetched (HTTP 402), so only the code (S1) was read. Source rules: a shooting star is a bar where (1) Open >= Close; (2) Close - Low < lower_bound * |Close - Open| (little or no lower wick); (3) |Open - Close| < body_size * reference body (small body); (4) High - Open >= 2 * (Open - Close) (upper wick at least 2x the body); (5) Close >= previous Close and (6) previous Close >= the Close before it (uptrend); (7) the NEXT bar's High <= the star's High and (8) the NEXT bar's Close <= the star's Close. The trade is a short. It exits when |Close / entry - 1| > stop_threshold (0.05, the same rule takes profit and stops loss) or after holding_period = 7 bars. Defaults: lower_bound 0.2, body_size 0.5, stop_threshold 0.05, holding_period 7. WHY THIS VERSION: the previous attempt ran the conjunction on VOD.USEQ alone and produced no trades in the sandbox (1,401 sessions). A firing-rate check, which measures feasibility and says nothing about performance, shows why. Across all of VOD.USEQ's 9,557 daily bars the confirmed signal holds only about 6 times. On 25 long-lived US large caps since 2005 it holds about 0.044 times per name-year. The binding conditions are 1+2+5 together (a red candle that closes at its low after a gap up), not the body size: relaxing body_size from 0.5 to 2.0 only lifts the rate to 0.063. Any single US name gives about one trade per 20 years. CHANGES, each labelled: (A) UNIVERSE: we keep the user's market, Vodafone on its US listing, VOD.USEQ (VOD.L/UKEQ is not enabled on this platform). VOD.USEQ is the primary instrument and is always eligible. The identical rule also runs independently on every S&P 500 member AS OF EACH BAR (self.index_member(iid, 'sp500') / universe_at(index='sp500'), former members included where bars exist, parameters['point_in_time_universe']=True; extra_instruments = `python -m src.data.listings sp500 --start 1996-01-01 --end <run end> --with-data`). That gives about 20-25 signals per year. This is the only way to test the source's exact pattern definition with a usable sample, and it avoids survivorship bias. (B) CAUSALITY: conditions 7 and 8 use the next bar, and the source books the short at the star's own close (look-ahead). Here the star is bar t-1. Bar t is the confirmation bar: High_t <= High_{t-1} and Close_t <= Close_{t-1}. The short is decided at the close of bar t and fills at the NEXT session's open (next_open_fill, supported on USEQ). (C) BODY REFERENCE (condition 3): the source compares against abs(np.mean(Open - Close)) over the WHOLE dataset. That uses future data, and because the signed mean is near zero, condition 3 almost never holds. Here the reference is the mean of |Open - Close| over the previous body_lookback = 20 sessions of the same name, excluding the star bar. This follows the author's own comment that the body test should be relaxed. (D) BOOKKEEPING: one net short per name. A new star on a name already short is ignored. Overlapping signals in the source's signal column are not reproduced. (E) EXIT REFERENCE: the +/-5% test uses the actual fill price as entry; the source used the star's close. Exits are tested on daily CLOSES, as written, not intrabar. The exit is decided at the close and fills at the next session's open. (F) SIZING (platform default; the source has none): each short is 10% of current equity in notional, whole shares, at most 10 open shorts. Gross short exposure is therefore at most 100% of equity on the 2x Reg-T margin account. If more than the free slots signal on one day, take them in ascending ticker order, so selection never uses performance. Risk control route (b): signal exits (the +/-5% close rule plus a 7-session time limit) with capped sizing. Losing 5% plus an overnight gap on a 10% position costs about 0.5-1% of equity. Zero commissions; spread and impact are modelled about 1 bp per side. Dividends are not in PnL, which slightly flatters shorts (stated as a risk).