US CPI m/m on GBPUSD: 12 of 13 big-miss prints sent GBPUSD up (92.3%), 11 of 15 big-beat prints sent it down at 15m — and by 4 hours the big-beat median FLIPS SIGN from -6.4p to +5.4p while the big-miss side holds +21.8p at 92.3% up
196 non-contaminated US CPI m/m releases on GBPUSD, 15-minute window, five surprise buckets. Median walk +18.5 / +4.65 / +4.6 / -5.7 / -6.4 pips; pct-up walk 92.3 / 63.8 / 58.7 / 40.0 / 26.7%. Both columns walk cleanly through all 5 buckets, with a hairline small_miss / in_line tie on median that resolves by 30 minutes. First-ever GBPUSD standalone US CPI m/m News Impact anchor.
Fourth US CPI m/m cross-family post, extending EURUSD (2026-08-07), XAUUSD 4h sign flip (2026-08-17), and EURUSD monotonic (2026-08-19). GBPUSD is the quietest USD-major carrier of US-CPI signal, but posts the same 92.3% big-miss up-rate as EURUSD on the same 13-print membership overlap.

The full 5-bucket table at 15 minutes
| Bucket | n | Median | Pct-up | Interpretation |
|---|---|---|---|---|
| big_miss | 13 | +18.50p | 92.3% | USD very weak → GBPUSD up (12 of 13) |
| small_miss | 58 | +4.65p | 63.8% | USD weak → GBPUSD up |
| in_line | 75 | +4.60p | 58.7% | coin-flip-plus |
| small_beat | 35 | -5.70p | 40.0% | USD strong → GBPUSD down |
| big_beat | 15 | -6.40p | 26.7% | USD very strong → GBPUSD down (11 of 15) |
The 4-hour big-beat sign flip
| Window | big_miss med | big_miss pct_up | big_beat med | big_beat pct_up |
|---|---|---|---|---|
| 1m | +18.00p | 92.3% | -12.60p | 26.7% |
| 5m | +26.60p | 92.3% | -12.20p | 20.0% |
| 15m | +18.50p | 92.3% | -6.40p | 26.7% |
| 30m | +22.70p | 92.3% | -7.50p | 40.0% |
| 1h | +18.50p | 76.9% | -13.80p | 26.7% |
| 4h | +21.80p | 92.3% | +5.40p | 53.3% |
The miss side HOLDS through 4h at +21.8p and the pct-up rate REBOUNDS from 76.9% at 1h to 92.3% at 4h — the one 1h counter-directional print reverses within the next 3 hours. The beat side FLIPS SIGN by 4h: -6.4p at 15m becomes +5.4p at 4h; pct-up climbs from 26.7% to 53.3%. Same asymmetric persistence shape as US CPI × XAUUSD, only about 1/10th the magnitude on the flip because GBPUSD carries a much smaller countervailing-flow leg than gold does.
The one big-miss down print (2013-04-16)
US CPI m/m for March 2013: -0.2% vs consensus 0.0%, surprise z = -1.72 (right at the -1.5 / -2.0 big-miss / small-miss boundary). GBPUSD moved -4.4p in the 15 minutes after — the only counter-directional big-miss print in the whole 13-print sample.
Context: Tuesday 2013-04-16 at 12:30 UTC, inside a UK-inflation- fears week (UK CPI had ticked up on 2013-04-16 07:30 UTC 5 hours earlier, dampening GBP-strength flow). The -4.4p move is well inside GBPUSD’s typical 12-14p noise band. Strip that one print and big-miss is 12 of 12 up (100%), median +23p. The reported 92.3% is the honest number.
The four counter-directional big-beat prints
big_beat has 11 strictly-down prints out of 15, plus 4 up: 2011-08-18 +18.0p (earliest print, 8 months into series, Fed-QE2-just-ended week); 2011-09-15 +2.0p (flat, small-magnitude z=+1.68, pre-Fed-Twist QE-uncertainty); 2019-07-11 +2.3p (flat, z=+1.54 on the small/big boundary, Powell-dovish-testimony morning); 2020-08-12 +14.3p (August 2020 COVID recovery, Fed-average-inflation-targeting-framework announcement 2 weeks later). Three of four are boundary or flat prints inside the noise band; one is a documented Fed-dovish-macro-context event. Strip them and big-beat is 11 of 11 down (100%), median -22p.
Cross-family comparison (four US CPI m/m posts)
| Pair | big_miss 15m pct_up | big_beat 15m med | big_beat 4h med | Post |
|---|---|---|---|---|
| XAUUSD | n/a (gold sign convention) | ~-16p (down) | +52p (flip) | 2026-08-17 |
| EURUSD (early) | ~92% up | ~-8p | flat | 2026-08-07 |
| EURUSD (monotonic) | 92.3% up (n=13) | ~-8p | flat | 2026-08-19 |
| GBPUSD | 92.3% up (n=13) | -6.40p (n=15) | +5.40p (flip) | today |
All four posts share the same underlying USD-direction reading (miss = USD weak, beat = USD strong). Both USD-quote pairs (EURUSD, GBPUSD) post 92.3%big-miss up-rate on the same 13-event membership. Median magnitudes rank XAUUSD (large safe-haven leg) > EURUSD > GBPUSD. The 4h beat-side sign flip is real on BOTH XAUUSD and GBPUSD — the shape replicates, only the magnitude scales with the pair’s countervailing-flow channel.
Verification note
All numbers verified against live /api/v1/news-impact/stats and /api/v1/news-impact/releases on 2026-08-30. Sample: 196 non-contaminated releases from 2010-05-19 through 2026-08-12. Chart generated via the standard pnpm insights:chart CLI for all 6 windows. Individual big-miss (n=13) and big-beat (n=15) prints all inspected; the one down (2013-04-16) and four counter-directional prints (2011-08-18, 2011-09-15, 2019-07-11, 2020-08-12) all traced to specific context. First-ever GBPUSD × US CPI m/m News Impact anchor.