Fortinet Inc (FTNT) stock analysis

How has Fortinet's share price moved?

Is Fortinet undervalued? The value diligence check

Every value-investing signal this site computes for this stock, gathered in one place: the same real numbers from the tools below, not a new score.

• Margin of safety (DCF) -144.0%
• P/E vs. its own history 61.2x · the middle Real range: 32.8x–98.9x over 5 years (net income per diluted share from each fiscal year's 10-K, paired with the real closing price at that fiscal year-end).
• Wall St. analyst rating Hold · 3.24/5 51 analysts this month: 5 strong buy, 9 buy, 31 hold, 5 sell, 1 strong sell (Finnhub). Down from 3.27 last month.
• Altman Z″-Score (bankruptcy risk) 1.88 · Grey zone
• Earnings quality (is the profit real?) Strong · all 5 checks clean Beneish M-score −2.65 · accruals −7.3% of assets · 143% of profit arrived as cash · stock comp 4.1% of revenue · share count −1.5% a year. From the latest 10-K (year to Dec 2025) - see the Earnings Quality Screener for how each check is scored.
• Shareholder yield (cash back to owners) +1.5% net Latest fiscal year (2025): dividends 0.0% + buybacks 1.8% − stock comp 0.2%, as a share of today's market cap. Over 14 years its split-adjusted share count fell 7%. See Shareholder Yield Leaders.
• Capital needed to grow (See's test) None needed · capital fell while profit grew Operating profit $129M → $1.7B, capital needed −$281M → −$367M, 2016–2025 (3-year averages); its capital is negative: customers and suppliers fund it. Buffett's See's Candies needed $0.42 per $1 of new profit, FlightSafety $3.20, a typical grower about $5. See Capital-Light Compounders.
• PEG (growth at a reasonable price) 3.53 · Well above fair P/E 61.2× ÷ 17.3% a year of growth behind it. 368th lowest of 447 stocks with a usable PEG. Lynch's fair value is a PEG of 1; a very high PEG usually means almost no growth, a very low one a profit spike. See PEG Ratio Ranking.
• Compounder lenses (4) 2 of 4 · misses cash back, price Capital-light growth: cleared; Profit is real: cleared; Cash to owners: not cleared (+0.8% a year net); Fair price (PEG): not cleared (PEG 3.53, over 1.5). See Compounders at a Fair Price, which also lets you move the PEG bar.
• Value trap check Clear
• Munger's Inversion Check 3 flags
• Standing vs. sector peers 3 of 6 measures above the median Compared with the 43 other technology stocks this site tracks: 3 in the top third, 2 in the bottom third.

How does Fortinet compare with its peers?

3 of 6 measures sit above the median of the 43 other technology stocks tracked here, 3 in the top third and 2 in the bottom third.

• P/E ratiolower is cheaper · peer median 26.0× 61.2× ✕31st of 39
• Free-cash-flow yieldhigher is cheaper · peer median 3.8% 2.4% ✕31st of 44
• Return on equityhigher is better · peer median 24% 188% ✓4th of 44
• Net marginhigher is better · peer median 16.9% 28.2% ✓10th of 44
• Revenue growthhigher is better, year on year · peer median 19.1% 18.8% –23rd of 44
• Debt / equitylower is safer · peer median 0.60 0.32 ✓14th of 44

Peers are the stocks this site tracks in the same sector group, not every listed competitor. The bar runs from the weakest peer (left) to the strongest (right); the tick is the middle. Measures that don't apply to a sector (cash-flow yield for banks, debt for financials) are left out.

What would Buffett & Lynch say?

Quantitative approximations of each investor's documented approach, not endorsed by either investor or their estates - commentary, not this site's actual ranking criteria. Buffett never published a numeric checklist: only 2 of his 8 checks here trace to his own documented concepts ("owner earnings," from his 1986 shareholder letter, and "price is what you pay, value is what you get," his case against fixed P/E/P/B ceilings) - the other 6 (ROE, debt, margins, growth, interest coverage) use commonly-cited thresholds that are not numbers he himself published. The 8 hard filters below (plus the Munger check and Graham margin of safety) are this site's real, mechanical screen and are computed completely independently of the checklists above.

Berkshire Hathaway's own filing

Which of the 8 value filters does Fortinet pass?

• Market Cap > $25B $129.9B
• Trailing P/E < 25 61.23
• PEG Ratio < 1.5 3.53
• Price/Book < 8 83.72
• Price/Sales < 7 17.25
• EPS Growth YoY > -5% +43.9%
• vs 50-day MA (±12%) Not evaluated †
• vs 200-day MA (±12%) Not evaluated †

What is Fortinet's margin of safety?

-163% on 2026-10-07 → -144% on 2026-10-23 (5 weekly readings).

Where is Fortinet in its 52-week range?

What is the short interest in Fortinet?

12,503,836 shares short as of 2026-09-30 (FINRA settlement date). Reported twice a month, so this only changes roughly every two weeks, not daily.

What could go wrong with Fortinet? Munger's inversion check

"Invert, always invert." Instead of reasons to buy, these are reasons to hesitate, not a verdict, and not everything worth knowing about a business.

• Margin of safety, even in the bull case -44%
• Short interest under 5% of float 2.1%
• Passes most of the 6 fundamental filters 2/6 passed
• Price run-up backed by value, not just momentum +131% off 52wk low
• Debt/equity stable since 2020 0.00 → 0.81

Doesn't cover circle of competence, management quality, or accounting concerns: those need judgment, not data.