Fortinet, Inc.
MX ˙ BMV ˙ US34959E1091
SecurityMX:FTNT / Fortinet, Inc.
InstitutionBlair William & Co/il
Latest Disclosed Ownership156,820 shares
Latest Disclosed Value $ 12,815,330
Blair William & Co/il ownership in FTNT / Fortinet, Inc.

On May 8, 2026 - Blair William & Co/il filed a 13F-HR form disclosing ownership of 156,820 shares of Fortinet, Inc. (MX:FTNT) valued at $12,815,330 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 160,633 shares of Fortinet, Inc.. This represents a change in shares of -2.37% during the quarter.

Blair William & Co/il has a history of taking positions in derivatives of the underlying security (FTNT) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:FTNT / Fortinet, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-08 2026-03-31 13F FORTINET COM 34959E109 156,820 -3,813 -2.37 12,815 0.47 0.0367
2026-02-17 2025-12-31 13F FORTINET COM 34959E109 160,633 -26,212 -14.03 12,756 -18.80 0.0342
2025-11-12 2025-09-30 13F FORTINET COM 34959E109 186,845 -15,618 -7.71 15,710 -26.61 0.0418
2025-07-24 2025-06-30 13F FORTINET COM 34959E109 202,463 876 0.43 21,404 10.31 0.0595
2025-05-09 2025-03-31 13F FORTINET COM 34959E109 201,587 -11,683 -5.48 19,405 -3.70 0.0585
2025-02-12 2024-12-31 13F FORTINET COM 34959E109 213,270 -10,764 -4.80 20,150 15.98 0.0586
2024-11-12 2024-09-30 13F FORTINET COM 34959E109 224,034 -1,316 -0.58 17,374 27.92 0.0510
2024-08-12 2024-06-30 13F FORTINET COM 34959E109 225,350 1,538 0.69 13,582 -11.17 0.0419
2024-05-09 2024-03-31 13F FORTINET COM 34959E109 223,812 6,912 3.19 15,289 20.43 0.0480
2024-02-12 2023-12-31 13F FORTINET COM 34959E109 216,900 -232,090 -51.69 12,695 -51.81 0.0433
2023-11-09 2023-09-30 13F FORTINET COM 34959E109 448,990 -28,704 -6.01 26,347 -27.04 0.1010
2023-08-11 2023-06-30 13F FORTINET COM 34959E109 477,694 98,684 26.04 36,109 43.35 0.1323
2023-05-12 2023-03-31 13F FORTINET COM 34959E109 379,010 68,904 22.22 25,189 66.14 0.1006
2023-02-10 2022-12-31 13F FORTINET COM 34959E109 310,106 -21,658 -6.53 15,161 -6.99 0.0659
2022-11-09 2022-09-30 13F FORTINET COM 34959E109 331,764 30,990 10.30 16,300 -4.22 0.0749
2022-08-10 2022-06-30 13F FORTINET COM 34959E109 300,774 240,377 397.99 17,018 -17.55 0.0755
2022-05-13 2022-03-31 13F FORTINET COM 34959E109 60,397 -10,501 -14.81 20,640 -19.00 0.0723
2022-02-14 2021-12-31 13F FORTINET COM 34959E109 70,898 -473 -0.66 25,481 22.25 0.0799
2021-11-12 2021-09-30 13F FORTINET COM 34959E109 71,371 4,189 6.24 20,843 30.25 0.0710
2021-08-12 2021-06-30 13F FORTINET COM 34959E109 67,182 -5,960 -8.15 16,002 18.63 0.0555
2021-05-13 2021-03-31 13F FORTINET COM 34959E109 73,142 4,005 5.79 13,489 31.36 0.0509
2021-02-09 2020-12-31 13F FORTINET COM 34959E109 69,137 -12,782 -15.60 10,269 6.40 0.0376
2020-11-06 2020-09-30 13F FORTINET COM 34959E109 81,919 1,686 2.10 9,651 -12.38 0.0409
2020-08-12 2020-06-30 13F FORTINET COM 34959E109 80,233 -1,077 -1.32 11,014 33.89 0.0525
2020-05-11 2020-03-31 13F FORTINET COM 34959E109 81,310 12,691 18.49 8,226 12.29 0.0514
2020-02-13 2019-12-31 13F FORTINET COM 34959E109 68,619 -585 -0.85 7,326 37.91 0.0377
2019-11-12 2019-09-30 13F FORTINET COM 34959E109 69,204 474 0.69 5,312 0.59 0.0306
2019-08-13 2019-06-30 13F FORTINET COM 34959E109 68,730 205 0.30 5,281 -8.22 0.0302
2019-05-14 2019-03-31 13F FORTINET COM 34959E109 68,525 -9,569 -12.25 5,754 4.62 0.0351
2019-02-14 2018-12-31 13F FORTINET COM 34959E109 78,094 1,534 2.00 5,500 -22.14 0.0402
2018-11-13 2018-09-30 13F FORTINET COM 34959E109 76,560 -4,936 -6.06 7,064 38.84 0.0433
2018-08-13 2018-06-30 13F FORTINET COM 34959E109 81,496 4,127 5.33 5,088 22.75 0.0346
2018-05-15 2018-03-31 13F FORTINET COM 34959E109 77,369 -3,265 -4.05 4,145 17.66 0.0293
2018-02-14 2017-12-31 13F FORTINET COM 34959E109 80,634 -13,925 -14.73 3,523 3.95 0.0239
2017-11-13 2017-09-30 13F FORTINET COM 34959E109 94,559 -17,302 -15.47 3,389 -19.08 0.0254
2017-08-04 2017-06-30 13F FORTINET COM 34959E109 111,861 28,602 34.35 4,188 34.66 0.0314
2017-05-10 2017-03-31 13F FORTINET COM 34959E109 83,259 83,259 3,110 0.0251
2017-02-14 2016-12-31 13F FORTINET COM 34959E109 0 -6,048 -100.00 0 -100.00
2016-11-14 2016-09-30 13F FORTINET COM 34959E109 6,048 -23,928 -79.82 223 -76.45 0.0020
2016-08-08 2016-06-30 13F Fortinet COM 34959E109 29,976 1,484 5.21 947 8.60 0.0088
2016-05-16 2016-03-31 13F FORTINET COM 34959E109 28,492 9,100 46.93 872 44.37 0.0082
2016-02-16 2015-12-31 13F FORTINET COM 34959E109 19,392 -12,500 -39.19 604 -55.39 0.0057
2015-11-12 2015-09-30 13F FORTINET COM 34959E109 31,892 -22,414 -41.27 1,354 -39.66 0.0117
2015-08-03 2015-06-30 13F FORTINET COM 34959E109 54,306 -8,587 -13.65 2,244 2.09 0.0034
2015-05-11 2015-03-31 13F FORTINET COM 34959E109 62,893 62,893 0.00 2,198 0.0034
2015-02-05 2014-12-31 13F FORTINET COM 34959E109 0 -21,854 -100.00 0 -100.00
2014-11-04 2014-09-30 13F FORTINET COM 34959E109 21,854 -3,483 -13.75 552 -13.21 0.0009
2014-08-01 2014-06-30 13F FORTINET COM 34959E109 25,337 1,700 7.19 636 22.31 0.0010
2014-05-06 2014-03-31 13F FORTINET COM 34959E109 23,637 -17,700 -42.82 520 -34.18 0.0009
2014-02-11 2013-12-31 13F FORTINET COM 34959E109 41,337 21,050 103.76 790 92.21 0.0013
2013-11-12 2013-09-30 13F FORTINET COM 34959E109 20,287 -3,124 -13.34 411 0.49 0.0007
2013-08-07 2013-06-30 13F FORTINET COM 34959E109 23,411 23,411 409 0.0008
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2017-11-13 2017-09-30 13F FORTINET OPTION Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-08-04 2017-06-30 13F FORTINET OPTION Call 300 0.00 11 -8.33 n/a n/a n/a
2017-05-10 2017-03-31 13F FORTINET OPTION Call 300 12 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.