Earnings-Day Moves: What Seventeen Large-Cap Stocks Show
Microsoft’s stock rose +15.5% the day it last reported, on Jul 29, priced around 27.5 times trailing earnings. Cintas, a name a fraction of Microsoft’s size, has averaged only a 1.7% swing on its own reporting days, at a richer multiple of 40.3 times. If an expensive stock were the one supposed to jump, those two numbers argue against it before I have opened the rest of the data.
A stock’s price-to-earnings ratio tells me almost nothing about how far it will move on the day it reports; what tells me more is whether the business locks in its revenue months or years in advance, or has to re-win the customer’s decision every quarter.
I pulled the trailing average size of the one-day earnings move for seventeen large companies I track through this site’s own market data, the absolute value of the swing so a beat and a miss count the same, alongside each name’s trailing price-to-earnings ratio and its most recent reported move. None of it is from memory; every figure below is current as I write this in mid-September 2026. I run this comparison a few times a year, mainly to size positions ahead of a print rather than to guess which direction the stock goes, which this kind of history cannot tell anyone.
The pattern that comes out is not the one I expected going in.
Seventeen companies, one trading day each
Sorted by average move, the group runs from Advanced Micro Devices at 11.4% down to Cintas at 1.7%. The plain average across all seventeen names is 5.1%, a single number that hides more than it explains, which is the reason for breaking the group apart in the sections below rather than stopping here.
| Ticker | Company | Trailing P/E | Avg earnings-day move | Last reported move |
|---|---|---|---|---|
| AMD | Advanced Micro Devices | 143.5x | 11.4% | -7.0% (Aug 4) |
| MSFT | Microsoft | 27.5x | 8.1% | +15.5% (Jul 29) |
| QCOM | Qualcomm | 20.3x | 7.5% | -2.6% (Jul 29) |
| NFLX | Netflix | 22.6x | 7.3% | -7.3% (Jul 16) |
| DIS | Disney | 21.2x | 6.6% | +3.6% (Aug 5) |
| CI | Cigna Group | 11.4x | 6.4% | -3.0% (Jul 30) |
| WMT | Walmart | 38.7x | 6.1% | -9.2% (Aug 20) |
| MNST | Monster Beverage | 41.4x | 6.1% | -4.0% (Aug 6) |
| GOOGL | Alphabet-A | 17.5x | 5.0% | -7.1% (Jul 22) |
| NVDA | NVIDIA | 28.1x | 4.8% | +8.7% (Aug 26) |
| SBUX | Starbucks | 55.4x | 3.0% | +1.6% (Jul 29) |
| AAPL | Apple | 38.5x | 2.9% | -7.4% (Jul 30) |
| TJX | TJX Companies | 23.6x | 2.8% | -4.2% (Aug 19) |
| SO | Southern | 20.6x | 2.8% | -1.8% (Jul 30) |
| WM | Waste Management | 29.9x | 2.6% | -1.2% (Jul 28) |
| COST | Costco | 45.0x | 2.1% | -3.9% (May 28) |
| CTAS | Cintas | 40.3x | 1.7% | +4.4% (Jul 15) |
Price tag sorts the movers backward
Split the group at a trailing multiple of 35 and something close to backward shows up. The seven pricier names, AMD, Monster Beverage, Walmart, Starbucks, Apple, Costco and Cintas, average a 4.7% swing on earnings day. The other ten average 5.4%. That is close to the opposite of what I would have guessed walking in, since an expensive stock is supposed to be the volatile one, with more of its price resting on a distant growth assumption that one quarter can dent.
Cigna makes the point sharply. It trades at 11.4 times trailing earnings, the cheapest multiple on this list by a wide margin, yet it has averaged a 6.4% earnings-day move, more than Alphabet’s 5.0% at a modestly higher multiple of 17.5, and well above Apple’s 2.9% at more than three times Cigna’s price-to-earnings ratio. A cheap multiple is not a low-volatility badge. Sometimes it just means the market has already priced the next print as close to a coin flip.
The names at the very top of the table run on their own logic, separate from price. AMD’s 11.4% average sits inside a chip cycle where a single sentence about data-center demand can swing the stock by double digits in either direction, and I read its 143.5 times trailing multiple as earnings still working back from a weak prior year rather than runaway enthusiasm for the stock itself. Netflix, at 7.3%, moves on subscriber and engagement numbers that management chooses how much to disclose each quarter, which leaves room for surprise no matter what the multiple says. Qualcomm’s 7.5% average has more to do with how much of its licensing and chip revenue still depends on a small number of large customers, Apple chief among them, than with its unremarkable 20.3 times earnings. None of these three would look risky from the price-to-earnings column alone.
This year’s prints ran hotter than the trailing average
Eight of these seventeen most recent reports moved the stock by more than its own trailing average, and the misses skew toward the mega caps that are usually the calmest ones on the list. Apple fell -7.4% against a 2.9% average, more than double. Walmart fell -9.2% against a 6.1% average. Alphabet fell -7.1% against a 5.0% average. Microsoft went the other way, rising +15.5% against its own 8.1% average, and Nvidia rose +8.7% against a 4.8% average.
That’s six names right there, and Costco and TJX also moved past their own averages on their last reports. Not a majority of the list, but close to half, and weighted toward the names an investor would ordinarily treat as the boring anchors of a portfolio.
I don’t have enough quarters of this particular stretch to call it a new regime instead of a run of noisier ones. If the next round of reports drops back toward the older trailing averages instead of confirming this one, the case for sizing positions around 2026’s wider swings weakens, and the calmer historical numbers in the table above go back to being the better guide. That is the condition that would prove this post wrong, and it is worth checking again once Cintas, Costco and the rest of this list have reported another full round.
A contract client is calmer than a discount rack
The three calmest names on the list, Cintas, Waste Management and Southern, share something a multiple does not capture: most of the revenue is locked in before the quarter even starts. Cintas bills under uniform and facility-services contracts that typically run one to five years, a point I leaned on when I looked at its multiple on its own. Waste Management collects under municipal and commercial hauling agreements with built-in price escalators. Southern is a regulated utility whose rates are set by state commissions, not renegotiated by a sales team every ninety days. Averaged together, those three move 2.6%-to-2.8% on an earnings day, roughly 2.4% as a group. The other fourteen names average 5.7%, more than double that.
None of that is a new idea to anyone who has followed a utility or a waste hauler for long. What did stand out to me is how cleanly it separates from the price-tag story above. Cintas is, at the same time, one of the more expensive names on this list and one of the calmest on earnings day, because the multiple and the reason someone pays it are two different questions with two different answers.
TJX lands in the same calm neighborhood at 2.8%, despite running an off-price retail model that sounds nothing like a utility. I read that as a different route to the same outcome. TJX’s buying is opportunistic and spread across thousands of vendors, so one bad category rarely swings the whole quarter, and the company has a long habit of guiding conservatively enough that the actual print stops being a coin flip; I made a version of this case comparing Costco, TJX, Walmart and three other retailers earlier this year. Costco, at 2.1%, is the calmest name on the list outside the contract trio, mostly because membership renewal rates shift by tenths of a percentage point a year, not by whatever happened in the most recent quarter.
Sizing the position, not the direction
None of this is a reason to duck earnings-day risk on the names that carry it. A volatile compounder is usually worth holding through the print rather than selling out of nerves the week before. What a table like this one changes is how I size around the print, not whether I own the stock.
Ahead of an AMD or a Qualcomm report, I would treat an 8% to 11% move as the base case in either direction and keep the position small enough that the outcome does not force a decision I would regret either way. Ahead of a Cintas or a Waste Management report, there is little reason to adjust anything at all; a 2% swing rarely changes what looks right the next morning. That’s the whole difference in one sentence.
A position that could not survive a 10% move overnight, in either direction, has no business being full-sized into an AMD or a Cigna print. That sounds obvious written down, but the arithmetic of a 6% or 7% drop on a full position is a harder lesson moving through it than any table teaches in advance. Disney sits in a milder version of the same bucket, averaging 6.6%, and I’d guess that split reflects streaming-subscriber trends and park attendance moving on separate schedules rather than together, which is part of why a position in it deserves less room than the multiple alone would suggest. The same logic runs through the reverse-DCF math I use on expensive stocks: a rich multiple on a low-volatility, contract-based business is asking a different question of an investor than a rich multiple on a name that can drop 7% before lunch.
The next print I would use as a test
Cigna reports again in the fourth quarter. If that print moves the stock by something close to its own 6.4% average, I would read that as confirmation the earnings-day risk here is a recurring feature of the business rather than a one-off. A move under 3%, in either direction, would tell me the market has already priced the uncertainty out, and the discount to peers has less reason to hold at 11.4 times earnings. Until that report lands, I am sizing Cigna as one of the noisier names on this list, not one of the safe ones its price-to-earnings ratio alone would suggest.
Analysis and opinion only, not investment advice. Figures come from each company’s most recent quarterly filings, searchable on SEC EDGAR for Cintas and Cigna, and price-to-earnings ratios and average earnings-day moves are current as of mid-September 2026 and will shift as new quarters report.
Sources: Price-to-earnings ratio (SEC Investor.gov glossary) (https://www.investor.gov/introduction-investing/investing-basics/glossary/price-earnings-pe-ratio) · How to read a company's 10-K (SEC Investor.gov) (https://www.investor.gov/introduction-investing/investing-basics/glossary/10-k)