CACI vs LDOS: Which Is the Better Buy in 2026?
Last updated August 2026
Short answer
LDOS is the larger of the two ($14.54B market cap): the incumbent the market prices for continued execution (8.82x forward earnings, beta 0.55). CACI is the smaller challenger ($11.00B), actually pricier on forward earnings (16.15x): 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.
CACI vs LDOS: 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 | CACI | LDOS | What it tells you |
|---|---|---|---|
| Market cap | $11.00B | $14.54B | Size. The larger name is the incumbent; the smaller has more room to grow and more to prove. |
| Forward P/E | 16.15 | 8.82 | 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 | 20.53 | 10.57 | 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 | 0.54 | 0.55 | 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 | 25% of range | 16% 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 | 2.57 | 2.90 | How much you pay over book value. Very high can signal an asset-light, high-return business or a rich price. |
Reading it: LDOS 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 CACI and LDOS 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. CACI and LDOS 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 CACI and LDOS 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 CACI International (CACI) do?
CACI International provides expertise and technology to US government and allied customers, concentrated in national security, defense, and intelligence. Its work spans signals and geospatial intelligence, electronic warfare, secure communications, software and systems engineering, cyber, and enterprise IT modernization, and roughly the large majority of revenue comes from federal agencies (Department of Defense and the intelligence community). The March 2026 completion of the ~$2.6 billion all-cash ARKA Group acquisition pushed CACI further into space-based sensing, geospatial intelligence, and agentic AI software, adding about 1,100 employees including a large specialized software-engineering base.
What does Leidos Holdings (LDOS) do?
Leidos Holdings is a large government services and technology contractor that builds and runs mission systems for U.S. federal agencies and allied governments. Its work spans intelligence and digital modernization, cybersecurity, defense systems, homeland security (including airport and border screening technology), and health services such as medical exams and health IT. Roughly the bulk of its revenue comes from the U.S. government, making it a prime contractor on long-duration programs rather than a commercial-product company.
CACI vs LDOS: 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.
- CACI drivers: Long backlog and recurring government demand; Shift toward higher-margin technology and software.
- LDOS drivers: Large backlog and revenue visibility; Margin expansion and cash generation.
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: CACI derives the large majority of revenue from the US government, so budget delays, continuing resolutions, shutdowns, or shifts in defense and intelligence priorities can directly pressure growth. For LDOS, the overwhelming majority of Leidos revenue comes from the U.S.
CACI or LDOS: 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 CACI if you believe its drivers more; LDOS 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 CACI and LDOS guides.
CACI vs LDOS: the full fundamentals
CACI. Trailing revenue was about $9.2 billion as of the March 2026 quarter, up from roughly $8.6 billion in fiscal 2025 (year ended June 2025), and management guided fiscal 2026 revenue toward $9.5 billion to $9.6 billion. As of early July 2026 the market capitalization was near $11 billion at a share price around $500, a trailing P/E near 25x and a forward P/E closer to 20x, reflecting a premium typical of scaled, backlog-rich defense-technology contractors.
LDOS. In its most recent quarter (fiscal Q1 2026, ended early April 2026), Leidos posted about $4.4 billion in revenue, non-GAAP EPS of roughly $3.13, and adjusted EBITDA margin near 14%, and it raised full-year guidance. The stock trades at a low double-digit trailing P/E, a discount to the broader market that reflects its slow-growth, government-dependent profile. Figures are approximate and change with new filings and price moves.
Headline figures (approximate, JULY 2026): CACI shows revenue (ttm) ~$9.2B, fy2026 revenue guidance ~$9.5B to $9.6B, net income (fy2025) ~$500M, market cap ~$11.1B; LDOS shows revenue (ttm) ~$17.5B, fy2026 revenue guidance ~$18.0B to $18.4B, latest quarter revenue ~$4.4B (up ~4% YoY), total backlog ~$48B.
The bottom line: CACI vs LDOS
CACI and LDOS 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 CACI and LDOS exposure against your real portfolio. It is not an investment adviser.
Wondering how CACI or LDOS 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 CACI International with AI
Connect the broker you already use and ask Walnut's AI how CACI 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 CACI and LDOS?
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CACI International provides expertise and technology to US government and allied customers, concentrated in national security, defense, and intelligence. Leidos Holdings is a large government services and technology contractor that builds and runs mission systems for U.S. 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 CACI or LDOS the better stock?
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Neither is universally better. LDOS is the larger incumbent; CACI 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, CACI or LDOS?
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On forward P/E (as of August 2026), CACI trades at 16.15x and LDOS at 8.82x, so LDOS 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 CACI and LDOS?
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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 CACI vs LDOS?
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CACI: CACI derives the large majority of revenue from the US government, so budget delays, continuing resolutions, shutdowns, or shifts in defense and intelligence priorities can directly pressure growth. A meaningful share of revenue rides on competitively recompeted contracts, and lost recompetes or protests can create lumpy results. The company uses debt to fund sizable acquisitions such as ARKA, so leverage, integration execution, and interest costs are real considerations. Margins can be affected by contract mix, transaction expenses, and labor cost inflation for cleared technical talent. Finally, the stock trades at a premium to some defense-services peers, so multiple compression is possible if growth or margins disappoint. LDOS: The overwhelming majority of Leidos revenue comes from the U.S. government, so budget delays, continuing resolutions, sequestration scenarios, and shifting administration priorities can directly pressure results. Contracts are frequently recompeted, and losing a large program or seeing an award protested can create lumpy revenue swings. Margins can be squeezed on fixed-price and cost-reimbursable work if execution slips or labor costs rise. The company also faces growing competition from both traditional peers and large commercial cloud and AI firms moving into federal work. Finally, its modest valuation reflects limited growth, so multiple expansion is not guaranteed even if execution stays solid.
Walnut is informational, not investment advice. This page is descriptive and not a recommendation to buy or sell CACI or LDOS; figures are approximate and dated (as of August 2026). Verify current data before investing.