The Central Bank Surprise Playbook

A rate decision that matches consensus barely moves anything — the market had already priced it in over the weeks before the meeting. What moves prices is the surprise component: the gap between what the central bank actually did or said and what futures markets were already implying beforehand. Traders measure this surprise directly using short-term rate futures (like fed funds futures), comparing the implied rate just before and just after the announcement, and that delta becomes the input to almost every reaction model.

A dovish surprise — a cut, or softer forward guidance than expected — typically weakens the currency, lifts equities (especially rate-sensitive growth names), and steepens the yield curve as short rates fall faster than long rates. A hawkish surprise does the reverse: currency strengthens, equities wobble, and the curve flattens as short rates jump. Bonds react almost mechanically to the surprise size; equities react to the surprise filtered through what it implies about growth, since a hawkish surprise driven by a strong economy can still be equity-positive.

The other pattern worth knowing is that the press conference often moves markets more than the printed statement, because forward guidance — the described path over future meetings — carries more information about future rates than the single decision in front of you.