UK GDP (Aug YY) 2.1% vs. Exp. 1.7% (Prev. 1.8%)

A UK GDP beat of this size sits in the established pattern where the monthly series, not the quarterly, drives the intraday repricing: the annual figure derives from rolling monthly prints, so the trade runs through the front end of the gilt curve and the SONIA strip, with sterling following the rates differential rather than the growth story itself. The distinction worth drawing is between a beat driven by the volatile components, health output and industrial swings, and one carried by services, since only the latter has historically shifted the MPC's read on domestic momentum. The base effect matters here: annual comparisons of this vintage can flatter or flatter in reverse depending on what rolled out of the window, so the three-month-on-three-month rate and any revisions to prior months carry more signal than the headline YY. Follow-ons are the composition detail and how the print feeds the Bank's near-term forecast round, where above-consensus growth alongside sticky services inflation has in past cycles argued for holding restrictive policy longer. As with most UK activity beats, the gilt and sterling response has tended to fade quickly when the detail is soft, so the breakdown is the tell.