Fortinet, Inc.

The full register, from 13F filings

The Register tab above is hand research: a dozen holders, each traced to the filing it came from. This asks the same question of the whole market for the quarter ended 31-mar-2026, where 1,300 managers reported a position. Broad where the research is deep, and shallow in the ways a 13F always is.

Built from 13F filings, which report US listed, long, US custodied positions only. A register from this source is a floor rather than a level: a holder's true position can be far larger, as BlackRock's ASML stake shows at 1.28m shares in a 13F against 26.3m in its 13G/A. Holdings held through derivatives, outside US custody, or below a manager's reporting obligation do not appear. Where a holder is marked as a family, its total sums several separate filing entities and describes something no single filing describes; the constituent entities and their share counts are listed so the total can be checked. That roll-up can legitimately exceed the family's own Schedule 13G, because a 13G is filed by one legal entity: Vanguard reports Alphabet through ten advisory entities, and The Vanguard Group Inc itself reported zero after its January 2026 disaggregation.

What a reader needs to know to read these numbers

• Fortinet is founder-led. Ken Xie (co-founder, Chairman and CEO) and Michael Xie (co-founder, President and CTO) are brothers; the 2026 proxy states there are no other family relationships among any directors or officers. Fortinet has a single class of common stock: the 2026 proxy states stockholders 'cast one vote for each share of common stock held,' and no Class B or dual-class structure was found anywhere in the 10-K or proxy (explicit searches for 'Class B', 'dual class' and 'dual-class' returned zero hits). The founders' influence is therefore a function of large economic ownership, not enhanced voting rights: Ken Xie individually holds 9.84% and Michael Xie 7.70% (after the Foundation double-count adjustment below) of a single one-vote-per-share class, a combined economic position of roughly 17.5% before adding any other director or officer.
• The Xie Foundation double-count. The Xie Foundation (a non-profit) holds 11,481,918 FTNT shares. Both Ken Xie and Michael Xie serve as officers/directors of the Foundation and are each separately deemed a beneficial owner of its full stake under SEC rules, so the proxy's individual rows for both brothers each include the full 11,481,918 shares, while both brothers disclaim any pecuniary interest in it. Per the rule that a rolls_up_into container can only be named once, Michael Xie's row is reduced by 11,481,918 shares (to 56,493,094, 7.70%) and Ken Xie's row is left at its full as-filed value (72,188,518, 9.84%); the reduction is corroborated arithmetically, since summing every individually listed proxy-table row (140,770,673) exceeds the proxy's own reported group total (129,288,755) by exactly 11,481,918 shares, i.e. the group total already counts the Foundation once, confirming the reduction lands on the correct amount rather than an assumption.
• Vanguard case: the parent, Vanguard Group Inc (CIK 0000102909), filed Form 13F-NT (a notice carrying no holdings) for the quarter ended 30 Jun 2026. Per the rule for this case, the position is reported entirely by successor entities and the two identified successors are summed into one 'The Vanguard Group' row rather than substituted or listed separately: Vanguard Capital Management LLC (40,663,961 shares) and Vanguard Portfolio Management LLC (24,844,685 shares), totaling 65,508,646 shares.
• Capital Group family: all three entities were checked. Only Capital World Investors holds FTNT (2,739,976 shares); Capital International Investors and Capital Research Global Investors were each confirmed at zero via direct CUSIP inspection and a 'FORTI' name-fragment search of their full info tables. No parent files a 13F-NT for this family, so the single holding entity is reported as a roll-up, not a proxy aggregate.
• Both T. Rowe Price entities were checked. T. Rowe Price Associates, Inc. (CIK 0000080255) holds 1,616,922 shares; its info table reports value in thousands of dollars, and the raw $248,392 figure was rescaled by 1000 to $248,392,000 (implied price $153.62, matching the ~$153.6 cluster seen across every other Q2 2026 13F filer of this CUSIP). T. Rowe Price Investment Management, Inc. (CIK 0001897612), the separate registrant in the same family, was confirmed to hold zero FTNT shares.
• BlackRock case: BlackRock's combined 13F-HR is now filed under a newer entity, BlackRock, Inc. (CIK 0002012383), not the older CIK 0001364742 (last filed 13F for Q1 2025) nor any of the several BlackRock subsidiary CIKs that each now file 13F-NT naming CIK 0002012383 as the other reporting manager. The register uses this current 13F-HR (62,242,221 shares, 30 Jun 2026) rather than the 2026 proxy's own cited figure, a stale Schedule 13G/A from 26 Jan 2024 showing 54,206,558 shares, per the brief's preference for the most current filed source.
• Stock split check: Fortinet's most recent stock split was a 5-for-1 split effective 23 Jun 2022, well before every figure used in this file (13F positions as of 30 Jun 2026, proxy beneficial ownership as of 31 Mar 2026, share counts as of 28 Jul 2026). No stock split, forward split or dividend language was found in the FY2025 10-K or the Q2 2026 10-Q (explicit term searches returned zero hits for 'split' in both). All register share counts and shares_outstanding in this file sit on one consistent, current, post-2022-split basis.
• Percentages for the two founder rows and the officers-group row are recomputed against 733,713,653 common shares outstanding as of 28 Jul 2026 (the Q2 2026 10-Q cover page), for consistency with the rest of the register, rather than the proxy's own denominator of 733,955,815 shares as of 31 Mar 2026 (the proxy's record date). The two denominators differ by only about 242,000 shares (a difference of less than 0.04 percentage points), consistent with ordinary buybacks between the two dates rather than any split or restatement.
• Holdings are empty by design, a sourced finding rather than a gap. The FY2025 10-K and Q2 2026 10-Q were both searched for 'equity method', 'non-marketable', 'strategic investment', 'privately held', and 'joint venture'. Fortinet's only historically material equity-method position was a 50.8% stake in Linksys Holdings, Inc., acquired for the remaining equity on 31 Jan 2025; Linksys is now a 100%-owned, consolidated subsidiary and is correctly excluded as a wholly owned operating subsidiary, not a holding. As of 31 Dec 2025, the 10-K states Fortinet held 'one equity method investment' (down from two at 31 Dec 2024, the second having been the pre-acquisition Linksys stake), but does not name this remaining investee anywhere in the filing, and states that 'remaining investments in privately held companies are recorded at cost and ... were not material' at both 31 Dec 2025 and 31 Dec 2024. The Q2 2026 10-Q likewise names no investee. 'Joint venture', 'strategic investment' (in the investment sense) and 'non-marketable' each returned no matching disclosure of a named, sized position in either filing. Per the rule against assigning a combined or immaterial balance to an unnamed investee, no holdings row is created for this position.
• Self-gate check (computed the way the chart computes it): 10 register rows. Raw shares sum with the officers-group container reduced to its residual (129,288,755 minus 128,681,612 shares rolled up from Ken Xie and the reduced Michael Xie row, leaving a residual of 607,143) gives a total of 320,916,327 shares against 733,713,653 shares outstanding, or 43.74%. This sits at the high end of, but within, the roughly 25-45% expected band for a founder-led company with two large founder stakes.