AAOI vs COHR: Which Is the Better Buy in 2026?
Last updated August 2026
Short answer
COHR is the larger of the two ($51.43B market cap): the incumbent the market prices for continued execution (31.71x forward earnings, beta 2.04). AAOI is the smaller challenger ($7.57B), cheaper on forward earnings (19.77x): 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.
AAOI vs COHR: 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 | AAOI | COHR | What it tells you |
|---|---|---|---|
| Market cap | $7.57B | $51.43B | Size. The larger name is the incumbent; the smaller has more room to grow and more to prove. |
| Forward P/E | 19.77 | 31.71 | 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. |
| Beta | 3.69 | 2.04 | 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 | 35% of range | 50% 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 | 6.73 | 4.81 | How much you pay over book value. Very high can signal an asset-light, high-return business or a rich price. |
Reading it: AAOI 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 AAOI and COHR 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. AAOI and COHR 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 AAOI and COHR 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 Applied Optoelectronics (AAOI) do?
Applied Optoelectronics, Inc. designs and manufactures optical communications products across two main markets: data-center transceivers (including 400G, 800G, and emerging 1.6T modules used in AI and cloud networks) and cable television (CATV) equipment such as DOCSIS 4.0 amplifiers and lasers. The company is vertically integrated, producing many of its own lasers and optical subassemblies, and positions itself as a US-based alternative to Asian optical suppliers for hyperscale customers building AI infrastructure.
What does Coherent Corp (COHR) do?
Coherent Corp, formerly II-VI and now trading as COHR on the NYSE, makes lasers, optical components, and high-speed transceivers used in AI data centers, telecom networks, industrial manufacturing, and semiconductors. Its largest and fastest-growing segment is Datacenter & Communications, which supplies the 800G and emerging 1.6T optical transceivers that connect GPUs and switches inside AI clusters, alongside a smaller Industrial segment covering lasers and materials.
AAOI vs COHR: 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.
- AAOI drivers: 800G and 1.6T data-center ramp; Hyperscale customer commitments.
- COHR drivers: AI datacom transceiver demand; Transition to 1.6T optics.
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: Customer concentration is severe: a small number of hyperscalers have historically driven the large majority of revenue, so a single procurement shift could sharply cut sales, as an earlier Amazon fallout showed. For COHR, cOHR trades at a high earnings multiple, so any slowdown in AI capital spending or a demand air pocket could hit the stock hard.
AAOI or COHR: 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 AAOI if you believe its drivers more; COHR 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 AAOI and COHR guides.
AAOI vs COHR: the full fundamentals
AAOI. AAOI trades at a high price-to-sales multiple (well above the broader communications-equipment average), reflecting expectations for the AI-driven 800G and 1.6T ramp rather than current earnings. It is smaller than optical peers like Coherent, Lumentum, and Fabrinet, so its valuation is more sensitive to a few large orders and to shifts in hyperscaler spending.
COHR. Coherent's revenue has accelerated on AI datacenter optics demand, with the Datacenter & Communications segment making up about three quarters of sales. The stock carries a high trailing multiple that reflects rapid earnings growth expectations, so the valuation depends heavily on that growth continuing. Figures are approximate and shift with each quarterly report and market moves.
Headline figures (approximate, July 2026): AAOI shows revenue (ttm) ~$500-560 million, q1 2026 revenue ~$151 million (up ~51% YoY), 2026 revenue guidance ~$1.1 billion+, non-gaap gross margin ~29%; COHR shows revenue (ttm) ~$6.3B, q3 fy2026 revenue ~$1.81B (up ~21% YoY), q3 fy2026 non-gaap eps ~$1.41, q4 fy2026 revenue guidance ~$1.91B to $2.05B.
The bottom line: AAOI vs COHR
AAOI and COHR 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 AAOI and COHR exposure against your real portfolio. It is not an investment adviser.
Wondering how AAOI or COHR 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 Applied Optoelectronics with AI
Connect the broker you already use and ask Walnut's AI how AAOI 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 AAOI and COHR?
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Applied Optoelectronics, Inc. Coherent Corp, formerly II-VI and now trading as COHR on the NYSE, makes lasers, optical components, and high-speed transceivers used in AI data centers, telecom networks, industrial manufacturing, and semiconductors. 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 AAOI or COHR the better stock?
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Neither is universally better. COHR is the larger incumbent; AAOI is the smaller challenger and looks cheaper 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, AAOI or COHR?
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On forward P/E (as of August 2026), AAOI trades at 19.77x and COHR at 31.71x, so AAOI 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 AAOI and COHR?
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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 AAOI vs COHR?
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AAOI: Customer concentration is severe: a small number of hyperscalers have historically driven the large majority of revenue, so a single procurement shift could sharply cut sales, as an earlier Amazon fallout showed. The company remains unprofitable at the net level with gross margins near 29%, and heavy capital spending plus a $250 million ATM equity program and convertible notes create meaningful dilution and balance-sheet risk. Competition from much larger and better-funded optical vendors, rapid technology transitions (400G to 800G to 1.6T), and the possibility that hyperscalers slow AI capex all add uncertainty. The stock is highly volatile and trades at a rich price-to-sales multiple that assumes flawless execution. COHR: COHR trades at a high earnings multiple, so any slowdown in AI capital spending or a demand air pocket could hit the stock hard. Revenue is concentrated among a small number of hyperscaler and networking customers, which creates order-timing and pricing risk. The optical components industry is cyclical and competitive, with pricing pressure from Chinese module makers and component rivals. The Industrial segment has been soft, and the company remains sensitive to macro conditions and semiconductor capital cycles. Execution on the 1.6T ramp and capacity expansion is not guaranteed.
Walnut is informational, not investment advice. This page is descriptive and not a recommendation to buy or sell AAOI or COHR; figures are approximate and dated (as of August 2026). Verify current data before investing.