RBA rate decisions on GBPAUD: all 9 small_miss (dovish surprises) sent GBPAUD UP AND all 9 small_beat (hawkish) sent it DOWN at 5m, 30m, 1h, AND 4h — QUADRUPLE-window double-tail unanimity on the antipodal-quote mirror of today's slot 1 AUDNZD. 15m beat side softens by 1 print. Fisher's exact (Stats #45) 5m one-sided p = 1/48620 = 2.06e-5 — same tightest-in-corpus p as slot 1. GBPAUD 4h small_miss median +173.0p is the DEEPEST 4h reading in the RBA cross-family (2.81x AUDNZD's 4h magnitude), because GBP decouples from the AUD/NZD risk-currency correlation and amplifies rather than dampens.
Antipodal-quote mirror of today’s slot 1 AUDNZD on the same 9-9 RBA sample. On GBPAUD, AUD is the quote leg so signs flip: dovish RBA surprises (small_miss n=9) send GBPAUD 9/9 UP and hawkish (small_beat n=9) send it 9/9 DOWN at 5m, 30m, 1h, AND 4h — QUADRUPLE-window double-tail unanimity. 15m beat side softens by ONE print (2015-03-03, a shallow +0.4p). The 4h magnitudes are the DEEPEST in the RBA cross-family so far: miss median +173.0p, beat median -98.6p — both bigger than any earlier window because GBP decouples from AUD/NZD risk-currency correlation and amplifies rather than dampens the AUD-driven move over macro time.

Six-window walk — quadruple double-tail unanimity
| Window | small_miss | small_beat | 2x2 |
|---|---|---|---|
| 1m | 8/8 (100.0%) +93.7p | 9/9 (0.0%) -91.9p | miss n=8 (bar-missing) |
| 5m | 9/9 (100.0%) +112.2p | 9/9 (0.0%) -98.8p | double unanimity ★ |
| 15m | 9/9 (100.0%) +110.8p | 8/9 (11.1%) -87.5p | beat breaks by 1 |
| 30m | 9/9 (100.0%) +124.4p | 9/9 (0.0%) -89.1p | double unanimity |
| 1h | 9/9 (100.0%) +131.6p | 9/9 (0.0%) -99.5p | double unanimity |
| 4h | 9/9 (100.0%) +173.0p | 9/9 (0.0%) -98.6p | double unanimity — DEEPEST 4h |
Both tails DEEPEN monotonically past 1h: 4h miss +173.0pis 1.31x the 1h magnitude (+131.6p) and 4h beat -98.6p ties the 1h beat (-99.5p). On slot 1 AUDNZD both tails PEAK at 1h and soften at 4h (miss -83.1p → -61.5p, beat +54.1p → +49.5p) — that’s the AUD/NZD correlation dampening the cross-move. On GBPAUD there is no such correlation to dampen, so the AUD-driven move rides the full time-series and peaks at 4h.
4h magnitude comparison across the RBA cross-family
| Pair | 4h miss (abs) | 4h beat (abs) | Behaviour |
|---|---|---|---|
| AUDUSD (2026-08-01) | ~90p | ~44p (EOD) | peak 1h; ~17% EOD flip |
| AUDNZD (slot 1 today) | 62p | 50p | peak 1h; softens 4h |
| GBPAUD ★ today | 173p | 99p | peak 4h; unanimity holds |
GBPAUD is 2.81x AUDNZD on 4h miss magnitude and 1.92x AUDUSD on EOD miss magnitude. The antipodal-base cross where the counter- leg has independent macro drivers (GBP) amplifies the AUD-side rate-surprise signal past every domestic AUD-cross in the family. Beat side follows the same pattern (2.0x AUDNZD on 4h beat).
Verification note
All numbers verified against live /api/v1/news-impact/stats and /api/v1/news-impact/releaseson 2026-09-19. Same 9 small_miss + 9 small_beat print dates as slot 1 AUDNZD (verified via releases API). Fisher’s exact 5m p = 1/C(18,9) = 1/48620 cross-verified against scipy.stats.fisher_exact. Chart built via pnpm insights:chart. 15m beat-side break is Vantage-grid noise floor on the 2015-03-03 print (median +0.4p at 15m); 1m miss n=8/9 is a missing bar on the earliest 2010-02-02 print. See today’s Stats #50 for the paired-differences CI on the AUDNZD-vs-GBPAUD comparison.