How earnings season actually works.

— Why a beat can still tank the stock

A stock does not trade on the earnings number. It trades on the gap between the earnings number and what the market already priced in. The consensus estimate is an average of what sell-side analysts put in writing before the print, and the stock has been drifting toward that estimate for weeks. By the time the report lands, the estimate is in the price. The only thing left to react to is the delta.

This is why a company can beat consensus and still fall. If the buy side was already expecting a bigger beat than the sell side was publishing, which is the whisper number in desk shorthand, then the published beat is actually a miss against the real expectation. Nobody publishes the whisper number, but the flow in the options market the week before a print tells you roughly where it sits. When the stock sells off on a beat, the whisper was higher than the consensus, and you just watched it clear.

The bigger lever is the guidance. A stock is the discounted value of all future cash flows, which means the current quarter is one data point in a very long series. When the CFO walks through the forecast for the next quarter or the next year, the market is quietly repricing every one of those future data points. A raised forecast multiplies through every future year. A cut does the same thing in reverse, and the reverse version is much louder. That is why the press release can look great and the stock can still end the day red.

The print is about yesterday. The call is about tomorrow. Tomorrow is what is being priced.

— What earnings season actually is

Every public company in the U.S. has to file financial results with the SEC four times a year. Three of those filings are 10-Qs, which are quarterly and unaudited. The fourth is the 10-K, which is the annual filing and is audited by an outside accounting firm. The 10-K is longer, more thorough, and comes with the risk factors section that public companies update once a year and lawyers love. The 10-Q is the quarterly update in between.

The calendar is not a suggestion. Most companies run on a fiscal year that matches the calendar year, so Q1 ends March 31 and the reports arrive in April and May. Q2 ends June 30 and prints in July and August. Q3 ends September 30 and prints in October and November. Q4 plus the full-year 10-K lands in January and February. The S&P 500 is large enough that at any given moment in those windows, a few dozen companies are reporting on the same afternoon.

The order inside each window is the tell. Big banks report first, because their accounting closes quickly and because the market wants the read on lending, deposits, and trading before anything else. Megacap tech lands in the second and third weeks, which is when the index-level narrative gets decided. Retailers report last, because their fiscal year ends in late January instead of December, which shifts their whole calendar back by about a month. This is also why you hear analysts talking about a retailer's Q4 in May. It is not a typo. It is the fiscal calendar being honest about when the holiday selling season actually ends.