QLYS vs TENB: How Qualys and Tenable Holdings Compare (2026)

Same yardstick, side by side (as of July 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.

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. QLYS and TENB 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 QLYS and TENB 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.

Qualys (QLYS) is a cloud-based cybersecurity company best known for vulnerability management. Its platform continuously scans an organization's IT assets (servers, endpoints, cloud workloads, web apps, and containers) to find security weaknesses, misconfigurations, and missing patches, then helps prioritize and remediate them. The flagship products are VMDR (Vulnerability Management, Detection and Response) and a growing suite covering cloud security posture, compliance, web application scanning, and patch management.

Full QLYS guide

Tenable Holdings is a cybersecurity company focused on exposure management: helping organizations find, prioritize, and reduce the vulnerabilities and misconfigurations that attackers could exploit. Its best-known product is Nessus, one of the most widely used vulnerability scanners in the industry, and its cloud platform Tenable One extends that capability across IT systems, cloud environments, operational technology, identities, and web applications. The company makes money primarily through subscriptions to its platform, generating recurring revenue as customers pay annually to continuously scan and assess their attack surface. Tenable's pitch is preventive: rather than detecting attacks after they happen, it helps organizations understand and shrink their exposure before attackers strike, and prioritize which weaknesses matter most. It serves enterprises, governments, and mid-market customers across many industries. Headquartered in Columbia, Maryland, Tenable competes in the broad and growing market for vulnerability and exposure management within the larger cybersecurity landscape.

Full TENB guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• QLYS drivers: Vulnerability management core; Platform expansion.
• TENB drivers: Exposure management and platform expansion; Recurring subscription revenue.

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: Qualys competes against larger, better-funded platforms (Tenable, Rapid7, CrowdStrike, Microsoft) that are bundling vulnerability and exposure management into broader security suites, pressuring standalone vendors. For TENB, cybersecurity is intensely competitive and consolidating.

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 QLYS if you believe its drivers more; TENB 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 QLYS and TENB guides.

QLYS. Qualys trades as a profitable, cash-generative SaaS security name rather than a hypergrowth disruptor. Its multiple reflects steady recurring revenue and high margins, balanced against slower growth than platform peers. Valuation tends to compress when growth decelerates and expand when cross-sell and exposure-management momentum reaccelerate.

TENB. Tenable trades on recurring revenue growth and free cash flow rather than GAAP earnings, which sit near breakeven due to stock-based compensation and reinvestment. The qualitative profile is a steady, profitable-on-a-cash-basis security vendor with a strong Nessus brand expanding into exposure management. Its more moderate valuation reflects mid-teens growth versus faster-growing platform peers.

Headline figures (approximate, early 2026): QLYS shows revenue (ttm) ~$650 million, revenue growth High-single to low-double-digit, operating margin ~30% (GAAP); higher non-GAAP, free cash flow margin Strong (often ~40% of revenue); TENB shows revenue (ttm) ~$900 million, revenue growth low-to-mid teens year over year, recurring revenue mix the large majority of revenue, gross margin ~75 to 80%.

QLYS and TENB 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 QLYS and TENB exposure against your real portfolio. It is not an investment adviser.