Amkor Technology Stock: 5 Straight Red Days, Down 22%
A five-day slide has erased billions in market value, raising questions about whether the selling has outpaced the company’s fundamentals.
A recent slide in Amkor Technology (AMKR) stock has erased about $3.3 billion from the company’s market value. The stock has now moved lower for 5 consecutive trading days, producing a cumulative loss of 22% over that period and bringing its market capitalization to about $12 billion.
For anyone holding the stock, this streak accounts for nearly the entire move over the last three months, during which the stock has returned -27.1%. Yet over the trailing twelve months, the stock’s return is still +108.1%.
How The Streak Stacks Up Against The S&P 500
Here is how AMKR stock stacks up against the S&P 500 over the streak and the periods around it:
| Return Period | AMKR | S&P 500 |
|---|---|---|
| 1D | -4.7% | -0.3% |
| 5D (Current Streak) | -21.9% | -1.2% |
| 1M (21D) | -26.3% | 3.2% |
| 3M (63D) | -27.1% | 2.4% |
| YTD 2026 | 21.7% | 11.8% |
| 2025 | 55.9% | 16.4% |
| 2024 | -20.8% | 23.3% |
| 2023 | 40.3% | 24.2% |
What does the data say about this price?
The move appears to be specific to the company. Over the same 5 trading days, the S&P 500 returned -1.2%. The market may be weighing a business that is still growing, with revenue over the last twelve months up 17.9%, ahead of the S&P 500 median of 8.4%. Its operating margin of 8.6% is below the S&P median of 18.4%.
Still, after the sell-off, AMKR trades at a price-to-earnings multiple of 21.4. That figure is below the S&P 500 median of 23.5, suggesting a valuation that is not stretched relative to the broader market, particularly for a company with its recent top-line growth.
How should I think about a streak like this?
A streak is not an instruction. It is a piece of information, telling you where momentum and market attention have been focused. It does not, by itself, tell you where the price is going next. The disciplined response is to do exactly what the numbers here allow: check the state of the business against the new, lower price.
A sharp move in either direction is an opportunity to re-evaluate whether the market’s reaction aligns with the company’s underlying performance. The answer is never in the streak itself, but in the comparison of price to fundamentals.
A slide like this always poses the same follow-up: which marked-down stocks are actually worth buying? Our Buy the Dip screen runs that test every day, flagging beaten-down names whose fundamentals still hold up.
Prefer the theme to this single name? Our ETF Scorecard shows how the technology funds stack up. It is still a concentrated bet on that one theme, though, which is exactly the gap the portfolio below closes.
Weakness In One Name Should Be Noise, Not News
For a diversified holder, a streak like this is a data point. For a concentrated one, it is a hole in the plan. The difference is never the stock; it is the portfolio built around it.
Building that portfolio is what the Trefis High Quality (HQ) Portfolio does: roughly 30 businesses with the cash generation and balance-sheet strength to absorb a bad month, selected and rebalanced by 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. Make the next streak, in either direction, someone else’s drama.