Arista Networks, Inc.
MX ˙ BMV ˙ US0404132054
SecurityMX:ANET / Arista Networks, Inc.
InstitutionMarshall Wace, Llp
Latest Disclosed Ownership397,000 shares
Latest Disclosed Value $ 48,743,660
Marshall Wace, Llp ownership in ANET / Arista Networks, Inc.

On May 14, 2026 - Marshall Wace, Llp filed a 13F-HR form disclosing ownership of 397,000 shares of Arista Networks, Inc. (MX:ANET) valued at $48,743,660 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 685,296 shares of Arista Networks, Inc.. This represents a change in shares of -42.07% during the quarter.

Marshall Wace, Llp has a history of taking positions in derivatives of the underlying security (ANET) in the form of stock options. The firm currently holds call options representing 2,700 of underlying shares valued at $331,506 USD and put options representing 1,500 of underlying shares valued at $184,170 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:ANET / Arista Networks, 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)
2026-05-14 2026-03-31 13F ARISTA NETWORKS COMMON STOCK 040413205 397,000 -288,296 -42.07 48,744 -45.72 0.0230
2026-02-13 2025-12-31 13F ARISTA NETWORKS COMMON STOCK 040413205 685,296 341,072 99.08 89,794 79.03 0.0817
2025-11-13 2025-09-30 13F ARISTA NETWORKS COMMON STOCK 040413205 344,224 -1,411,325 -80.39 50,157 -72.08 0.0509
2025-08-13 2025-06-30 13F ARISTA NETWORKS COMMON STOCK 040413205 1,755,549 -1,864,341 -51.50 179,610 -35.96 0.2023
2025-05-15 2025-03-31 13F ARISTA NETWORKS COMMON STOCK 040413205 3,619,890 2,896,765 400.59 280,469 250.91 0.3561
2025-02-13 2024-12-31 13F ARISTA NETWORKS COMMON STOCK 040413205 723,125 -41,066 -5.37 79,927 -72.75 0.0961
2024-11-14 2024-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 764,191 255,961 50.36 293,312 64.67 0.3573
2024-08-14 2024-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 508,230 183,230 56.38 178,124 89.01 0.2378
2024-05-15 2024-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 325,000 0 0.00 94,244 23.13 0.1435
2024-02-14 2023-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 325,000 -23,110 -6.64 76,541 19.54 0.1296
2023-11-14 2023-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 348,110 348,110 64,028 0.1297
2023-08-14 2023-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 0 -425,056 -100.00 0 -100.00
2023-05-15 2023-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 425,056 191,099 81.68 71,350 151.32 0.1516
2023-02-14 2022-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 233,957 -50,443 -17.74 28,391 -11.57 0.0639
2022-11-14 2022-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 284,400 -466,871 -62.14 32,106 -54.41 0.0703
2022-08-15 2022-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 751,271 -57,830 -7.15 70,425 -37.37 0.1449
2022-05-16 2022-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 809,101 95,903 13.45 112,447 9.68 0.2129
2022-02-14 2021-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 713,198 694,358 3,685.55 102,519 1,483.31 0.1893
2021-11-15 2021-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 18,840 260 1.40 6,475 -3.82 0.0269
2021-08-13 2021-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 18,580 17,128 1,179.61 6,732 1,436.99 0.0328
2021-05-17 2021-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 1,452 1,452 -92.19 438 -93.49 0.0020
2020-08-13 2020-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 0 -72,643 -100.00 0 -100.00
2020-05-15 2020-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 72,643 50,374 226.21 14,714 224.81 0.1470
2020-02-14 2019-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 22,269 22,269 -69.34 4,530 -69.21 0.0311
2019-08-14 2019-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 0 -477 -100.00 0 -100.00
2019-05-29 2019-03-31 13F/A-1 ARISTA NETWORKS COMMON STOCK 040413106 477 -14,918 -96.90 150 -95.38 0.0014
2019-05-14 2019-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 477 -14,918 150
2019-02-14 2018-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 15,395 14,315 1,325.46 3,244 1,030.31 0.0331
2018-12-06 2018-09-30 13F/A-1 ARISTA NETWORKS COMMON STOCK 040413106 1,080 1,080 -92.98 287 -91.15 0.0024
2018-11-14 2018-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 1,080 1,080 287
2018-08-14 2018-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 0 -8,792 -100.00 0 -100.00
2018-05-15 2018-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 8,792 8,792 2,245 0.0931
2017-02-10 2016-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 0 -3,440 -100.00 0 -100.00
2016-11-10 2016-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 3,440 -45,234 -92.93 293 -90.65 0.0021
2016-08-12 2016-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 48,674 48,674 1,314.94 3,134 969.62 0.0264
2016-05-13 2016-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 0 -30,070 -100.00 0 -100.00
2016-02-10 2015-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 30,070 23,123 332.85 2,341 450.82 0.0220
2015-11-12 2015-09-30 13F ARISTA NETWORKS COMMON STOCK 040413106 6,947 -1,214 -14.88 425 -36.28 0.0052
2015-08-14 2015-06-30 13F ARISTA NETWORKS COMMON STOCK 040413106 8,161 -82,075 -90.96 667 -89.52 0.0087
2015-05-11 2015-03-31 13F ARISTA NETWORKS COMMON STOCK 040413106 90,236 85,573 1,835.15 6,364 2,148.76 0.0829
2015-02-17 2014-12-31 13F ARISTA NETWORKS COMMON STOCK 040413106 4,663 4,663 283 0.0037
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
(%)
2026-05-14 2026-03-31 13F ARISTA NETWORKS EQUITY OPTION Call 2,700 -20.59 332 -25.62 n/a n/a n/a
2026-02-13 2025-12-31 13F ARISTA NETWORKS EQUITY OPTION Call 3,400 446 n/a n/a n/a
2023-05-15 2023-03-31 13F ARISTA NETWORKS EQUITY OPTION Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-02-14 2022-12-31 13F ARISTA NETWORKS EQUITY OPTION Call 10,800 12.50 1,311 20.96 n/a n/a n/a
2022-11-14 2022-09-30 13F ARISTA NETWORKS EQUITY OPTION Call 9,600 1,083 n/a n/a n/a
Disclosed Put 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
(%)
2026-05-14 2026-03-31 13F ARISTA NETWORKS EQUITY OPTION Put 1,500 -99.13 184 -99.19 n/a n/a n/a
2026-02-13 2025-12-31 13F ARISTA NETWORKS EQUITY OPTION Put 173,200 24,642.86 22,694 22,369.31 n/a n/a n/a
2025-11-13 2025-09-30 13F ARISTA NETWORKS EQUITY OPTION Put 700 102 n/a n/a n/a
2023-05-15 2023-03-31 13F ARISTA NETWORKS EQUITY OPTION Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-02-14 2022-12-31 13F ARISTA NETWORKS EQUITY OPTION Put 4,000 -66.67 485 -64.18 n/a n/a n/a
2022-11-14 2022-09-30 13F ARISTA NETWORKS EQUITY OPTION Put 12,000 1,354 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.