Verdict: Side-by-side breakdown using the Bull Rankings model. QLYS scored 71.8, ZS scored 36.0 — QLYS leads.
Compare another set
QLYS
Qualys, Inc.
Software - Infrastructure · Quality-Growth
71.8
$202.42 · $7.0B
fundamentals as of
Score gap
35.8
QLYS leads
ZS
Zscaler, Inc.
Software - Infrastructure · Quality-Growth
36
$233.73 · $38.1B
fundamentals as of
At a glance · who leads each dimension, on the model's own rules
Fastest growthZS+25.4%
Strongest balance sheetQLYS0.09
Highest qualityQLYS95 / 100
Largest discount to fair valueQLYS-11%
Side by side · every name on one set of axes
The model, pillar by pillar (0–100 each)
QLYS
stronger →← stronger
ZS
95
Qualityreturns · margins · balance sheet
36
74
Growthrevenue & earnings expansion
92
53
Valuevaluation vs sector peers
14
QLYS is stronger on 2 of 3 pillars.
Fundamentals, head-to-head
QLYS
ZS
$314mC
FCF
$852mC+
+10.4%B
Rev
+25.4%A-
0.09B+
D/E
0.72C+
35.1xB
P/E
—
3.33D
PEG
2.22C
—
P/S
11.4xC
Winner per row is the stronger grade; where grades tie, the better figure breaks it. A true tie or a missing value shows no highlight.
Valuation · DCF cross-check
QLYS
ZS
11% below
Price vs fair valuelower is cheaper
83% above
~5%/yr
Growth the price impliesyr-1 FCF growth, fading to 4% · lower = less priced in
~31%/yr
+3%
1-yr DCF upside
-58%
+12%
5-yr DCF upside
-45%
+28%
10-yr DCF upside
-19%
The DCF is a cross-check on intrinsic value, separate from the quality-growth score above.
Model signals
QLYS
Why this score
Buying back stock
Durable high returns
ZS
Why this score
Diluting shareholders
The companies
QLYSQualys, Inc.
Software - Infrastructure · $202.42 · beta 0.60
Why now
Software - Infrastructure · market cap $7.0b. Trading near 52-week high of $204.41 — momentum setup, limited technical margin of safety. Revenue growing +10%, comfortably above the S&P median. 18 sell-side analysts rate this a Hold with a mean 1-yr target of $179.36 (implying -11% upside).
Moat
Net margin 29% sits well above the S&P median (~11%) — suggests structural pricing advantage or cost discipline competitors can't quickly close. ROE 37% — top-decile capital efficiency. Either pricing leverage, low capital intensity, or aggressive buybacks; the durability story depends on which. FCF converts 152% of net income — earnings translate cleanly into cash.
Risk
Trading within 1% of the 52-week high — limited technical margin of safety; a momentum reversal would test conviction. Trailing P/E 35x sits well above the S&P median (~20x) — multiple compression is a real risk if revenue growth decelerates. Software — competitive moat is durable until it isn't; watch net revenue retention, gross margin trends, and any new market entrant with a fundamentally lower price point.
ZSZscaler, Inc.
Software - Infrastructure · $233.73 · beta 0.94
Why now
Software - Infrastructure · market cap $38.1b. Down 31% from 52-week high of $336.99 — deep drawdown territory. Revenue growing +25% — in hypergrowth territory. 44 sell-side analysts rate this a Buy with a mean 1-yr target of $233.38 (implying -0% upside).
Moat
Software economics — recurring revenue, embedded customer workflows, and high gross margin all compound the moat once a base account is won. Switching costs are the lever.
Risk
Currently unprofitable (margin -1.9%) — path to GAAP profitability is the core thesis risk. Down 31% from the 52-week high — the market is pricing in something the screen can't see; verify the bear case before sizing up. P/S 11.4x embeds aggressive forward growth — disappointing top-line guidance would compress the multiple hard.
Verdict — model-derived comparison
Generating verdict… typically 5–10 seconds
Not investment advice. The Bull Rankings publishes a quantitative ranking model and accompanying analysis for general informational purposes only. Nothing on this page is a recommendation to buy, sell, or hold any security; nothing is personalized to your circumstances, risk tolerance, or tax situation. Investing carries the risk of loss — invest at your own risk and consider consulting a licensed financial professional before acting on anything you read here. See terms and methodology for full disclosures.
Where QLYS and ZS diverge
On the headline score the gap is 35.8 points in favor of QLYS. They get there differently, though — each leads on a different pillar, so the better pick depends on which you weight.
QualityQLYS 95.2 · ZS 35.9QLYS +59.3
ValueQLYS 52.9 · ZS 14.1QLYS +38.8
GrowthQLYS 73.6 · ZS 91.9ZS +18.3
Pillars run 0–100. Value is judged against each company's own sector, so a Value score is a statement about a company relative to its own industry rather than to the other name here. A wide Value gap usually means the market already prices the difference in quality or growth — which is the trade-off this comparison comes down to.
Common questions
Is QLYS or ZS the better stock?
QLYS scores higher: QLYS 71.8, ZS 36.0 out of 100 on the Bull Rankings quality-growth score, which blends business quality, growth and valuation into one number. A higher score means a stronger business at a more reasonable price — it is not a price target or a recommendation.
Where do QLYS and ZS differ most?
The widest gap is quality, where QLYS leads by 59 points on the 0–100 pillar scale. Neither name sweeps: they trade the lead across the three pillars, so the comparison is a trade-off rather than one being better on every measure.
How are QLYS and ZS scored?
Each carries the same 0–100 quality-growth score used everywhere on the site, built from three pillars — quality (profitability and returns on capital), growth (revenue and earnings), and value (what you pay for them) — combined as a geometric mean, so a weak pillar cannot be papered over by a strong one.
How current is this comparison?
The whole universe is re-scored every trading day after the US market close, so the scores and fundamentals here reflect the latest published edition.