Reading an Option Chain Into a Fed Meeting: Why Macro-Event Vol Isn't Earnings Vol
Two different reasons for the same bump in IV
Pull up a chain in the days before an FOMC decision or a CPI print and you'll see the same signature you'd see before an earnings report: implied volatility ticks up in the expirations that straddle the event, then usually settles back down after. It's tempting to read the two the same way. They aren't. Earnings uncertainty is idiosyncratic and binary — one company reports one set of numbers at one scheduled moment, and nearly all of the uncertainty specific to that stock resolves in that instant. A Fed decision or an inflation print is systematic — it changes the discount rate and risk appetite applied to almost everything at once, so it nudges nearly every chain a little instead of nudging one chain a lot.
What actually moves on the chain beforehand
Compare ATM implied volatility in the weekly expiring right after the meeting (FOMC decisions land around 2pm ET) to the weekly expiring just before it, and you'll usually find a small step-up — a shallower version of the same term-structure kink an earnings date produces. It shows up far more clearly on broad index and ETF chains (SPX, SPY, QQQ) than on an individual stock with no direct exposure to the announcement. A single name's FOMC-week IV bump is mostly inherited beta to the index moving, not a company-specific reason for its own price to jump — which is exactly the opposite of an earnings bump, where the elevated IV belongs entirely to that one name.
The crush that doesn't always show up
Traders who've sold earnings vol often expect the same playbook to work around a Fed meeting: sell rich premium into the event, collect the crush once the print is out. It doesn't always play out that cleanly. An earnings report resolves almost all of its uncertainty in one release — the number is out, so IV collapses hard and fast the next session. A rate decision is followed by a press conference and forward guidance that the market has to keep digesting, sometimes for days, especially when the language is framed as data-dependent rather than settled. IV can stay elevated well past the announcement itself if the market treats the decision as the start of a narrative rather than the end of one — a real structural difference from the near-total, near-instant crush that follows a scheduled earnings print.
When two events land in the same week
Macro calendars don't space events out for anyone's convenience. A CPI print on Tuesday followed by an FOMC decision on Wednesday, or a jobs report bracketing a Fed week, shows up on a chain as two separate term-structure kinks close together instead of the single clean spike-then-crush shape you'd see around one earnings date. Reading that chain means checking IV expiration by expiration rather than assuming one event-implied move covers the whole week — the weekly expiring after CPI but before FOMC is pricing a different, smaller slice of uncertainty than the one expiring after both.
A systematic way to check it on a real chain
The mechanics borrow directly from an earnings-style expected-move calculation, just applied to the index or ETF instead of a single stock: take the ATM straddle price in the expiration right after the event, divide by the underlying's price, and that's the market's implied move for the event. The useful second step is comparing that number to how the index has actually moved historically on FOMC days specifically — not on a random day, and not on an earnings day for an unrelated stock — since realized macro-event moves often run smaller than earnings-day moves even when priced at a similar IV level going in. Whether that IV normalizes the next session or stays elevated is itself information: a quick reversion looks like an earnings-style crush, while IV holding up looks like the market still pricing an unresolved narrative. OptionScope's Greeks Matrix and expiration-by-expiration IV view make that comparison across the term structure without having to page through each expiration by hand.