Four times a year, every public company has to show its cards. For most stocks, earnings day brings a modest move. For a handful, it can mean a 20% gain or loss in a single session.
To find out which stocks tend to swing the most, our team at TIKR pulled the last eight earnings reports for every company in the Nasdaq 100 and measured how far each stock moved in the first trading session after its results came out. Across all those reports, the average move was 6.6% in one direction or the other, and the median was 5%.
Five companies that report between Oct. 21 and Oct. 28 have averaged moves of 8% or more. Here they are in the order they report:
A big average move says nothing about which direction the next one will go. What it does tell you is how often Wall Street has been caught off guard by these businesses lately. Here’s what’s going on with each one heading into its report, and why the reaction tends to be so sharp.
1. Texas Instruments
Reports: Oct. 21, after the close · Avg. earnings-day move: 8.7% · YTD: +56% · Forward P/E: 28.5
Texas Instruments (TXN) has been one of the quiet winners of 2026. The analog chipmaker’s stock is up about 56% this year as a long-awaited recovery in industrial and automotive demand finally showed up, with an added boost from AI data centers that need TI’s power-management chips. In the second quarter, revenue rose 23% year over year to $5.46 billion, and earnings per share (EPS) jumped 52% to $2.14. Trailing 12-month free cash flow more than doubled to $6.53 billion as TI’s multiyear factory buildout winds down and capital spending falls.
The stock has cooled off since June, though. Shares sit about 16% below their June high, and they slipped 3% after that strong July report on a day when worries about AI spending sank the Nasdaq more than 2%.
Why it swings: TI guides only one quarter at a time, and because it sells into nearly every corner of the economy, Wall Street treats that guidance as a read on the whole chip cycle. An upbeat outlook in April 2026 sent shares up 19% the next day. A cautious one in July 2025, when investors worried customers had pulled orders forward ahead of tariffs, knocked them down 13%. At 28.5 times forward earnings, the stock is now priced for the recovery to keep going.
What to watch: Analysts expect third-quarter revenue of about $5.93 billion, up 25% from a year ago, and EPS of about $2.43. Both sit near the middle of management’s guidance of $5.65 billion to $6.15 billion in revenue. The fourth-quarter outlook, and any comments on price increases, will probably matter more than the third-quarter numbers themselves.
2. PayPal
Reports: Oct. 27, before the open · Avg. earnings-day move: 8.0% · YTD: -3% · Forward P/E: 10.2
PayPal (PYPL) stock is roughly flat in 2026, which hides a wild ride. Shares plunged 20% on Feb. 3 after the company missed fourth-quarter revenue estimates, flagged weakness among its retail merchants, and named former HP CEO Enrique Lores as its new chief executive. Nine days later, the stock bottomed at $38.46, about 87% below its 2021 peak.
It has rallied nearly 50% since then. Takeover interest helped: Stripe and private equity firm Advent reportedly made a bid of $60.50 per share this summer, which PayPal rejected as too low, though Lores has said the company is open to offers. The business has steadied, too. Second-quarter revenue rose 5% to $8.68 billion, management said its branded checkout business had stabilized further, and PayPal raised its full-year adjusted EPS forecast to about $5.38.
Why it swings: At about 10 times forward earnings, PayPal is priced like a company whose growth days are behind it. That makes the stock extremely sensitive to any sign that branded checkout, the PayPal button at online checkouts and its most profitable business, is speeding up or slipping. Three of its last eight reports triggered drops of 8% or more.
What to watch: Analysts expect third-quarter revenue of about $8.70 billion, up 3%, and adjusted EPS of about $1.31, down slightly from a year ago. That’s in line with management’s guidance for a low-single-digit decline in EPS. With shares trading below the reported $60.50 offer, branded checkout growth and any update on strategic options will likely drive the reaction.
3. Teradyne
Reports: Oct. 27, after the close · Avg. earnings-day move: 11.5% · YTD: +62% · Forward P/E: 34.7
Teradyne (TER), which makes the machines that test chips before they ship, has become an AI stock. More than 60% of its second-quarter revenue was tied to AI, and revenue from testing compute chips jumped nearly 600% year over year. Total revenue more than doubled to $1.33 billion, and adjusted EPS climbed to $2.47 from $0.57 a year earlier. Shares are up 62% this year and 143% over the past 12 months.
The ride hasn’t been smooth. The stock peaked at $488 in June and now sits about 31% below that high, dragged lower by this month’s broad sell-off in chip stocks.
Why it swings: Teradyne’s orders depend on a relatively small number of big chip programs, and they rise and fall with new chip launches. That makes revenue lumpy and a single quarter’s guidance can reset estimates in a hurry. The stock’s recent reactions show it. Shares fell 19% the day after an April report that beat estimates. In July, they jumped more than 13% after hours on a strong report, opened nearly 15% higher the next morning, and still closed slightly down for the day. They rose 14% the session after that.
What to watch: Analysts expect third-quarter revenue of about $1.26 billion, up 64%, and adjusted EPS of about $2.05, in line with management’s guidance of $1.2 billion to $1.3 billion in revenue. Both figures are below the second quarter’s, so the focus will be on whether management sees growth picking back up in 2027, as Wall Street currently expects.
4. Seagate Technology
Reports: Oct. 27, after the close · Avg. earnings-day move: 10.2% · YTD: +130% · Forward P/E: 18.2
Hard drives were supposed to be yesterday’s technology. Instead, Seagate (STX) has been one of the market’s biggest winners as cloud companies building out AI infrastructure scramble for cheap, high-capacity storage. Its heat-assisted magnetic recording (HAMR) technology, which uses tiny lasers to squeeze more data onto each disk, lets it boost capacity without building costly new production lines. In the fiscal year that ended this summer, revenue rose 34% to $12.2 billion, gross margin widened 11 percentage points to 46%, and net income more than doubled to $3.18 billion.
The stock is up 130% this year, but October has been rough. Shares fell 11% on Oct. 2 after a Nikkei report that rival Toshiba plans to double its hard-drive capacity for AI data centers, then slid further in this month’s chip sell-off. The stock now trades about 40% below its June high of $1,145.
Why it swings: Not many companies make hard drives, so pricing and supply discipline drive profits. When prices hold and customers shift to bigger drives, margins expand quickly, and small changes in that outlook mean big changes in earnings. Analysts expect adjusted EPS to rise about 150% in calendar 2026. Investors also know storage has a long history of boom and bust, so every report becomes a referendum on how long this upswing lasts. Shares jumped 19% after both the October 2025 and January 2026 reports.
What to watch: Analysts expect fiscal first-quarter revenue of about $4.14 billion, up 57%, and adjusted EPS of about $7.40, right around management’s guidance of $4.1 billion and $7.30. The bigger question is whether Seagate can keep prices firm now that Toshiba is adding capacity.
5. Fortinet
Reports: Oct. 28, after the close · Avg. earnings-day move: 9.4% · YTD: +120% · Forward P/E: 48.9
Fortinet (FTNT) stock has more than doubled this year as businesses replace aging firewalls and add protection for AI workloads. In the second quarter, revenue rose 26% to $2.05 billion, billings jumped 33%, and product revenue, led by its FortiGate firewalls, surged 52%. Management raised its full-year revenue forecast to $8.02 billion to $8.18 billion, which would mean about 19% growth.
Shares hit an all-time high of $197 just last week before pulling back about 13%. Even after that dip, they’re up 132% from their January low.
Why it swings: A big chunk of Fortinet’s growth comes from hardware sales that move in cycles, and investors are always trying to figure out where the company sits in the current upgrade cycle. In August 2025, shares fell 22% in a day when management signaled the firewall refresh was already about halfway done. In May 2026, they jumped 20% after a big earnings beat. Good news can fade fast, too: after July’s strong report and raised forecast, the stock opened about 7% higher and closed up less than 1%.
What to watch: Analysts expect third-quarter revenue of about $2.06 billion, up 20%, and adjusted EPS of about $0.86, within management’s guidance of $0.83 to $0.87. Consensus calls for growth to slow to about 13% in the fourth quarter. With the stock at nearly 49 times forward earnings, billings and any early read on 2027 will likely matter most.
The bottom line
Big earnings moves cut both ways. Over the past two years, these five stocks rose after 21 reports and fell after 19, which is about as close to a coin flip as it gets. Four of them have also run up 56% to 130% this year, so the bar for a good reaction is high heading into these reports.
For long-term investors, a single day’s move rarely changes the investment case. If you own one of these stocks, it helps to know what kind of swing is normal so a 10% drop doesn’t shake you out of a business you still believe in. If you’re thinking about buying, waiting until after the report means giving up a guess on direction in exchange for a fresh quarter of information.
Stay on top of earnings season
Want to make sense of a company’s latest report? Pull it up on TIKR to see the new numbers alongside Wall Street’s estimates, then dig in from there. Read the call transcript to see how management explained the quarter, chart margins to see whether the trend is turning, or check what the stock trades at now that the price has moved.
