Teradyne Stock: 6 Straight Green Days, Up 21%
A recent run in Teradyne stock has investors watching, but the underlying business metrics tell their own story.
A six-day run in Teradyne (TER) stock has added about $11 billion to its market value. The stock has now moved higher for 6 consecutive trading days, gaining a cumulative 21% and bringing its total market capitalization to about $62 billion.
Teradyne stock trades at about $398.69 a share as of 9/22/2026. For anyone holding the shares, the streak has been a sharp, positive reversal of recent performance.
TER Versus The S&P 500, Streak And Beyond
Here is how TER stock stacks up against the S&P 500 over the streak and the periods around it:
| Return Period | TER | S&P 500 |
|---|---|---|
| 1D | 4.5% | -0.0% |
| 6D (Current Streak) | 21.1% | 1.9% |
| 1M (21D) | 6.1% | 1.2% |
| 3M (63D) | -5.1% | 5.4% |
| YTD 2026 | 106.2% | 13.4% |
| 2025 | 54.4% | 16.4% |
| 2024 | 16.5% | 23.3% |
| 2023 | 24.8% | 24.2% |
Do the fundamentals support this run?
The business fundamentals show strength relative to peers. Revenue over the last twelve months grew 57.9%, well above the 17.9% median for S&P 500 Information Technology stocks. The company’s operating margin of 30.9% also sits ahead of the 21.6% median. That performance comes at a premium valuation, with the stock trading at a price-to-earnings multiple of 54.2 versus a sector median of 36.2. The sources for this note do not show why the move happened.
This recent move is largely specific to the stock. Over the same six days, the S&P 500 returned +1.9%. While notable, such streaks are not unique in the current market; 9 other S&P 500 stocks are on similar or longer winning streaks.
How should an investor treat a streak?
A streak is information about momentum, not an instruction to act. It shows a stock has captured attention, but it guarantees nothing about the next move. This run is also a sharp change from recent performance; over the last three months, the stock returned -5.1%.
The disciplined response is to check the business against the price. The fundamental metrics noted here offer a starting point for that work, weighing the company’s growth and profitability against its current valuation.
A climb like this is worth respecting and worth testing: the momentum that lasts is usually the kind management itself is underwriting. Our Guidance Momentum screen tracks the stocks whose companies just raised their own forward numbers.
Those drawn to the strength but not the single-name risk have another route: a semiconductor ETF like SOXX holds the whole group, not the single stock. It is still a concentrated bet on that one theme, though, which is exactly the gap the portfolio below closes.
Momentum Is A Tailwind, Not A Plan
Riding a stock that rises every day feels effortless, and that is precisely the danger: the same momentum that built this run can reverse without notice, and one name’s reversal should never be able to reset your whole year.
That is what the Trefis High Quality (HQ) Portfolio is for: about 30 quality businesses screened for the fundamentals that survive momentum’s mood swings, held with rules. It has a track record of outpacing a benchmark that combines the three major indices – the S&P 500, S&P Mid-cap, and Russell 2000. Watch the runs; own the resilience.