Arista Networks, Inc.
MX ˙ BMV ˙ US0404132054
SecurityMX:ANET / Arista Networks, Inc.
InstitutionPrimecap Management Co/ca/
Latest Disclosed Ownership16,000 shares
Latest Disclosed Value $ 1,964,480
Primecap Management Co/ca/ ownership in ANET / Arista Networks, Inc.

On May 11, 2026 - Primecap Management Co/ca/ filed a 13F-HR form disclosing ownership of 16,000 shares of Arista Networks, Inc. (MX:ANET) valued at $1,964,480 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 16,000 shares of Arista Networks, Inc.. This represents a change in shares of 0.00% during the quarter.

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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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)
2026-05-11 2026-03-31 13F ARISTA NETWORKS COM SHS 040413205 16,000 0 0.00 1,964 -6.30 0.0015
2026-02-11 2025-12-31 13F ARISTA NETWORKS COM SHS 040413205 16,000 0 0.00 2,096 -10.08 0.0016
2025-11-12 2025-09-30 13F ARISTA NETWORKS COM SHS 040413205 16,000 -800 -4.76 2,331 35.68 0.0018
2025-08-11 2025-06-30 13F ARISTA NETWORKS COM SHS 040413205 16,800 0 0.00 1,719 32.05 0.0014
2025-05-09 2025-03-31 13F ARISTA NETWORKS COM SHS 040413205 16,800 0 0.00 1,302 -29.90 0.0011
2025-02-10 2024-12-31 13F ARISTA NETWORKS COM SHS 040413205 16,800 12,600 300.00 1,857 15.14 0.0014
2024-11-08 2024-09-30 13F ARISTA NETWORKS COM 040413106 4,200 0 0.00 1,612 9.51 0.0012
2024-08-09 2024-06-30 13F ARISTA NETWORKS COM 040413106 4,200 -2,950 -41.26 1,472 -28.99 0.0011
2024-05-14 2024-03-31 13F ARISTA NETWORKS COM 040413106 7,150 0 0.00 2,073 23.17 0.0015
2024-02-09 2023-12-31 13F ARISTA NETWORKS COM 040413106 7,150 0 0.00 1,684 27.98 0.0013
2023-11-13 2023-09-30 13F ARISTA NETWORKS COM 040413106 7,150 0 0.00 1,315 13.56 0.0011
2023-08-11 2023-06-30 13F ARISTA NETWORKS COM 040413106 7,150 0 0.00 1,159 -3.50 0.0010
2023-05-15 2023-03-31 13F ARISTA NETWORKS COM 040413106 7,150 0 0.00 1,200 38.41 0.0010
2023-02-13 2022-12-31 13F ARISTA NETWORKS COM 040413106 7,150 -250 -3.38 868 3.83 0.0008
2022-11-14 2022-09-30 13F ARISTA NETWORKS COM 040413106 7,400 0 0.00 835 20.32 0.0008
2022-08-11 2022-06-30 13F ARISTA NETWORKS COM 040413106 7,400 -3,200 -30.19 694 -52.89 0.0006
2022-05-11 2022-03-31 13F ARISTA NETWORKS COM 040413106 10,600 0 0.00 1,473 -3.35 0.0011
2022-02-11 2021-12-31 13F ARISTA NETWORKS COM 040413106 10,600 7,950 300.00 1,524 67.29 0.0011
2021-11-12 2021-09-30 13F ARISTA NETWORKS COM 040413106 2,650 0 0.00 911 -5.10 0.0006
2021-08-10 2021-06-30 13F ARISTA NETWORKS COM 040413106 2,650 -500 -15.87 960 0.95 0.0006
2021-05-14 2021-03-31 13F ARISTA NETWORKS COM 040413106 3,150 0 0.00 951 3.93 0.0007
2021-02-08 2020-12-31 13F ARISTA NETWORKS COM 040413106 3,150 0 0.00 915 40.34 0.0007
2020-11-13 2020-09-30 13F ARISTA NETWORKS COM 040413106 3,150 0 0.00 652 -1.51 0.0005
2020-08-13 2020-06-30 13F ARISTA NETWORKS COM 040413106 3,150 -2,400 -43.24 662 -41.10 0.0006
2020-05-14 2020-03-31 13F ARISTA NETWORKS COM 040413106 5,550 -19,950 -78.24 1,124 -78.33 0.0011
2020-02-14 2019-12-31 13F ARISTA NETWORKS COM 040413106 25,500 13,600 114.29 5,187 82.45 0.0038
2019-11-13 2019-09-30 13F ARISTA NETWORKS COM 040413106 11,900 100 0.85 2,843 -7.21 0.0023
2019-08-14 2019-06-30 13F ARISTA NETWORKS COM 040413106 11,800 0 0.00 3,064 -17.43 0.0023
2019-05-14 2019-03-31 13F ARISTA NETWORKS COM 040413106 11,800 5,750 95.04 3,711 191.06 0.0027
2019-02-12 2018-12-31 13F ARISTA NETWORKS COM 040413106 6,050 0 0.00 1,275 -20.71 0.0010
2018-11-13 2018-09-30 13F ARISTA NETWORKS COM 040413106 6,050 0 0.00 1,608 3.21 0.0011
2018-08-13 2018-06-30 13F ARISTA NETWORKS COM 040413106 6,050 0 0.00 1,558 0.84 0.0012
2018-05-14 2018-03-31 13F ARISTA NEETWORKS COM 040413106 6,050 250 4.31 1,545 13.10 0.0012
2018-02-13 2017-12-31 13F ARISTA NEETWORKS COM 040413106 5,800 4,000 222.22 1,366 300.59 0.0010
2017-11-13 2017-09-30 13F ARISTA NETWORKS COM 040413106 1,800 -1,200 -40.00 341 -24.05 0.0003
2017-08-11 2017-06-30 13F ARISTA NETWORKS COM 040413106 3,000 -200 -6.25 449 6.15 0.0004
2017-05-12 2017-03-31 13F ARISTA NETWORKS COM 040413106 3,200 -200 -5.88 423 28.57 0.0004
2017-02-13 2016-12-31 13F ARISTA NETWORKS COM 040413106 3,400 -4,900 -59.04 329 -53.40 0.0003
2016-11-14 2016-09-30 13F ARISTA NETWORKS COM 040413106 8,300 -66,500 -88.90 706 -85.34 0.0007
2016-08-12 2016-06-30 13F ARISTA NETWORKS COM 040413106 74,800 -700 -0.93 4,816 1.09 0.0051
2016-05-12 2016-03-31 13F ARISTA NETWORKS COM 040413106 75,500 15,000 24.79 4,764 1.17 0.0049
2016-02-12 2015-12-31 13F ARISTA NETWORKS COM 040413106 60,500 35,000 137.25 4,709 201.86 0.0048
2015-11-12 2015-09-30 13F ARISTA NETWORKS COM 040413106 25,500 -23,500 -47.96 1,560 -61.05 0.0017
2015-08-13 2015-06-30 13F ARISTA NETWORKS COM 040413106 49,000 0 0.00 4,005 15.89 0.0039
2015-05-14 2015-03-31 13F ARISTA NETWORKS COM 040413106 49,000 7,000 16.67 3,456 35.42 0.0034
2015-02-12 2014-12-31 13F ARISTA NETWORKS COM 040413106 42,000 0 0.00 2,552 -31.21 0.0026
2014-11-13 2014-09-30 13F ARISTA NETWORKS COM 040413106 42,000 -56,900 -57.53 3,710 -39.87 0.0040
2014-08-14 2014-06-30 13F ARISTA NETWORKS COM 040413106 98,900 98,900 6,170 0.0068
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.