AMKR vs IMOS: Which Is the Better Buy in 2026?
Last updated August 2026
Short answer
AMKR is the larger of the two ($12.39B market cap): the incumbent the market prices for continued execution (17.67x forward earnings, beta 2.21). IMOS is the smaller challenger ($1.65B), actually pricier on forward earnings (46.93x): more room to run, but more to prove. The real question is which set of drivers you believe, and whether owning one (or both) leaves you over-concentrated.
AMKR vs IMOS: the tie-breaker metrics
Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.
| Metric | AMKR | IMOS | What it tells you |
|---|---|---|---|
| Market cap | $12.39B | $1.65B | Size. The larger name is the incumbent; the smaller has more room to grow and more to prove. |
| Forward P/E | 17.67 | 46.93 | Valuation on next year's expected earnings, the same yardstick for both. Lower is cheaper for that growth; higher means the market is paying up. |
| Trailing P/E | 22.36 | 61.56 | Valuation on the last 12 months. A big drop from trailing to forward means the market expects earnings to jump, so more growth is already in the price. |
| Beta | 2.21 | 1.30 | Volatility vs the market. Above 1 swings harder than the index; below 1 is steadier. Higher beta means bigger drawdowns to hold through. |
| Price vs 52-week range | 37% of range | 51% of range | Where today's price sits between the 52-week low and high. Near the high is momentum with less margin of safety; near the low is out of favor or a discount, depending on why. |
| Price / book | 2.66 | 2.18 | How much you pay over book value. Very high can signal an asset-light, high-return business or a rich price. |
Reading it: AMKR is the cheaper of the two on forward earnings, but cheaper is not the same as better. Pair the valuation with growth (how far the forward P/E sits below the trailing P/E) and risk (beta) before you decide.
Before you buy: how AMKR and IMOS affect your concentration
The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. AMKR and IMOS share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.
This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined AMKR and IMOS exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.
What does Amkor Technology (AMKR) do?
Amkor Technology is one of the world's largest outsourced semiconductor assembly and test (OSAT) providers. After chips are fabricated at TSMC, Samsung, Intel, or other foundries, they need to be packaged (mounted in protective enclosures, connected to external pins) and tested before being sold. Amkor performs this packaging and testing for major customers including Apple, NVIDIA, Qualcomm, AMD, and others.
What does ChipMOS Technologies (IMOS) do?
ChipMOS Technologies provides back-end semiconductor services: it assembles and tests chips for fabless designers, integrated device manufacturers, and foundries. Its specialties include memory packaging and testing plus a leading position in chip-on-film (COF) packaging for display driver integrated circuits (DDICs) used in smartphone and TV panels, alongside services like wafer bumping, ball grid array (BGA), and wafer-level chip-scale packaging. The company runs facilities in Taiwan's Hsinchu and Southern Taiwan science parks and is listed both in Taipei (8150) and on Nasdaq as an ADR (IMOS).
AMKR vs IMOS: how do they differ?
Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.
- AMKR drivers: Advanced packaging for AI accelerators; US fab investment and onshore packaging.
- IMOS drivers: AI-driven memory demand; Chip-on-film and display-driver niche.
Which fits which kind of investor
A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: OSAT margins are structurally lower than fabless designers or pure foundries. For IMOS, chipMOS is a small OSAT competing against giants like ASE and Amkor and specialist peers like Powertech, so it lacks their scale, diversification, and pricing power.
AMKR or IMOS: which should you pick?
Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick AMKR if you believe its drivers more; IMOS if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the AMKR and IMOS guides.
AMKR vs IMOS: the full fundamentals
AMKR. Amkor trades at a modest multiple typical for the OSAT industry: thin margins, capex-heavy. The premium versus pure commodity OSATs comes from the advanced packaging mix shift and the US-domestic positioning.
IMOS. The trailing P/E looks extreme (near 98) because 2025 net profit fell about 65 percent year over year, compressing the earnings base, while the forward P/E of roughly 26 reflects expected recovery. The ADR rose more than 280 percent over the trailing 52 weeks on the AI memory upcycle, so the valuation now embeds a continued rebound in packaging and test demand.
Headline figures (approximate, early 2026): AMKR shows revenue (ttm) ~$6 billion, operating margin ~8% (thin, typical for OSAT), net income (ttm) ~$300 million, eps (ttm) ~$1.10; IMOS shows revenue (ttm) ~$792M, net income (ttm) ~$26M, gross margin ~12%, market cap ~$2.5B.
The bottom line: AMKR vs IMOS
AMKR and IMOS are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined AMKR and IMOS exposure against your real portfolio. It is not an investment adviser.
Wondering how AMKR or IMOS fits the portfolio you already own? Walnut is an AI investing app that connects your brokerage read-only and answers questions like that about your actual holdings: overlap, concentration, and how each position tracks the S&P 500. Compare the best AI portfolio analyzers or see the best AI investing apps in 2026.
Investing in Amkor Technology with AI
Connect the broker you already use and ask Walnut's AI how AMKR fits what you actually hold: whether you own it already through a fund, what it would do to your concentration, and how it has tracked the S&P 500. Read-only by default, and you approve anything before it reaches your broker.
FAQ
What is the difference between AMKR and IMOS?
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Amkor Technology is one of the world's largest outsourced semiconductor assembly and test (OSAT) providers. ChipMOS Technologies provides back-end semiconductor services: it assembles and tests chips for fabless designers, integrated device manufacturers, and foundries. They show up together because they share investment themes, but they are different businesses, so the better fit depends on which thesis you are expressing.
Is AMKR or IMOS the better stock?
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Neither is universally better. AMKR is the larger incumbent; IMOS is the smaller challenger and looks pricier on forward earnings. Walnut is informational, not investment advice. Compare what each does, the tie-breaker metrics above, and the risks, then decide which fits your thesis and what you already own.
Which is cheaper, AMKR or IMOS?
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On forward P/E (as of August 2026), AMKR trades at 17.67x and IMOS at 46.93x, so AMKR is the cheaper of the two on next year's expected earnings. A lower multiple is not automatically the better buy: a richer valuation can be justified by faster growth, and a lower one can reflect real risk. Weigh the multiple against how fast each business is compounding.
Should you own both AMKR and IMOS?
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Because they share themes, owning both concentrates you in that theme. That can be intentional (a focused bet) or accidental (less diversification than it looks). Walnut can show your combined exposure across both, and whether adding either over-concentrates you, before you buy.
What are the risks of AMKR vs IMOS?
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AMKR: OSAT margins are structurally lower than fabless designers or pure foundries. Capex requirements for advanced packaging are substantial. Customer concentration with the largest fabless designers is meaningful. IMOS: ChipMOS is a small OSAT competing against giants like ASE and Amkor and specialist peers like Powertech, so it lacks their scale, diversification, and pricing power. Its revenue is concentrated in two volatile end-markets, memory and consumer display drivers, meaning a downturn in smartphone sales or memory prices hits results directly and severely. Net profit already fell sharply in 2025 on higher non-operating expenses and lower operating profit, and gross margins are thin (around the low teens), so earnings are highly cyclical. As a Taiwan-based ADR, the stock also carries currency, geopolitical, and cross-listing risks, and after a very large one-year run the shares trade at a rich trailing valuation that assumes the memory and AI upcycle persists.
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Walnut is informational, not investment advice. This page is descriptive and not a recommendation to buy or sell AMKR or IMOS; figures are approximate and dated (as of August 2026). Verify current data before investing.