A10 Networks, Inc.
US ˙ NYSE ˙ US0021211018

SecurityATEN / A10 Networks, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership45,743 shares
Latest Disclosed Value $ 1,057,578
Citigroup Inc reports 29.70% decrease in ownership of ATEN / A10 Networks, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 45,743 shares of A10 Networks, Inc. (US:ATEN) valued at $1,057,578 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 65,064 shares of A10 Networks, Inc.. This represents a change in shares of -29.70% during the quarter. The current value of the position is $1,438,160 USD.

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 A10 NETWORKS COM 002121101 45,743 -19,321 -29.70 1,058 -8.09 0.0002
2026-02-13 2025-12-31 13F A10 NETWORKS COM 002121101 65,064 -15,408 -19.15 1,151 -21.23 0.0005
2025-11-10 2025-09-30 13F A10 NETWORKS COM 002121101 80,472 -34,901 -30.25 1,461 -34.59 0.0007
2025-08-11 2025-06-30 13F A10 NETWORKS COM 002121101 115,373 -37,502 -24.53 2,232 -10.61 0.0011
2025-05-12 2025-03-31 13F A10 NETWORKS COM 002121101 152,875 -14,034 -8.41 2,498 -18.69 0.0013
2025-02-12 2024-12-31 13F A10 NETWORKS COM 002121101 166,909 10,274 6.56 3,071 35.82 0.0018
2024-11-12 2024-09-30 13F A10 NETWORKS COM 002121101 156,635 44,080 39.16 2,262 45.12 0.0013
2024-08-12 2024-06-30 13F A10 NETWORKS COM 002121101 112,555 3,070 2.80 1,559 4.01 0.0010
2024-05-10 2024-03-31 13F A10 NETWORKS COM 002121101 109,485 2,124 1.98 1,499 6.02 0.0010
2024-02-09 2023-12-31 13F A10 NETWORKS COM 002121101 107,361 20,464 23.55 1,414 8.19 0.0010
2023-12-06 2023-09-30 13F/A-1 A10 NETWORKS COM 002121101 86,897 -55,388 -38.93 1,306 -37.06 0.0010
2023-11-09 2023-09-30 13F A10 NETWORKS COM 002121101 86,897 -55,388 1,306 0.0004
2023-08-10 2023-06-30 13F A10 NETWORKS COM 002121101 142,285 21,105 17.42 2,076 10.55 0.0014
2023-05-11 2023-03-31 13F A10 NETWORKS COM 002121101 121,180 1,384 1.16 1,877 -5.77 0.0013
2023-02-09 2022-12-31 13F A10 NETWORKS COM 002121101 119,796 -5,790 -4.61 1,992 19.57 0.0016
2022-11-10 2022-09-30 13F A10 NETWORKS COM 002121101 125,586 29,384 30.54 1,666 20.38 0.0012
2022-08-10 2022-06-30 13F A10 NETWORKS COM 002121101 96,202 -125,657 -56.64 1,384 -55.28 0.0010
2022-05-12 2022-03-31 13F A10 NETWORKS COM 002121101 221,859 -20,733 -8.55 3,095 -23.05 0.0019
2022-02-10 2021-12-31 13F A10 NETWORKS COM 002121101 242,592 -25,124 -9.38 4,022 11.44 0.0022
2021-11-10 2021-09-30 13F A10 NETWORKS COM 002121101 267,716 -28,233 -9.54 3,609 8.31 0.0021
2021-08-10 2021-06-30 13F A10 NETWORKS COM 002121101 295,949 7,958 2.76 3,332 20.38 0.0020
2021-05-13 2021-03-31 13F A10 NETWORKS COM 002121101 287,991 81,238 39.29 2,768 35.75 0.0018
2021-02-11 2020-12-31 13F A10 NETWORKS COM 002121101 206,753 64,769 45.62 2,039 125.55 0.0012
2020-11-12 2020-09-30 13F A10 NETWORKS COM 002121101 141,984 3,989 2.89 904 -3.73 0.0006
2020-08-12 2020-06-30 13F A10 NETWORKS COM 002121101 137,995 103,824 303.84 939 340.85 0.0007
2020-05-12 2020-03-31 13F A10 NETWORKS COM 002121101 34,171 19,227 128.66 213 106.80 0.0002
2020-02-12 2019-12-31 13F A10 NETWORKS COM 002121101 14,944 -7,327 -32.90 103 -33.55 0.0001
2019-11-08 2019-09-30 13F A10 NETWORKS COM 002121101 22,271 -621 -2.71 155 -0.64 0.0001
2019-08-12 2019-06-30 13F A10 NETWORKS COM 002121101 22,892 2,012 9.64 156 5.41 0.0001
2019-05-13 2019-03-31 13F A10 NETWORKS COM 002121101 20,880 29 0.14 148 13.85 0.0001
2019-02-12 2018-12-31 13F A10 NETWORKS COM 002121101 20,851 2,157 11.54 130 15.04 0.0001
2018-11-13 2018-09-30 13F A10 NETWORKS COM 002121101 18,694 6,611 54.71 113 50.67 0.0001
2018-08-10 2018-06-30 13F A10 NETWORKS COM 002121101 12,083 3,583 42.15 75 50.00 0.0001
2018-05-11 2018-03-31 13F A10 NETWORKS COM 002121101 8,500 1,111 15.04 50 -12.28 0.0000
2018-02-12 2017-12-31 13F A10 NETWORKS COM 002121101 7,389 5,516 294.50 57 307.14 0.0000
2017-11-13 2017-09-30 13F A10 NETWORKS COM 002121101 1,873 -9,295 -83.23 14 -85.11 0.0000
2017-08-11 2017-06-30 13F A10 NETWORKS COM 002121101 11,168 9,983 842.45 94 754.55 0.0001
2017-05-12 2017-03-31 13F A10 NETWORKS COM 002121101 1,185 -36,259 -96.84 11 -96.46 0.0000
2017-02-10 2016-12-31 13F A10 NETWORKS COM 002121101 37,444 33,302 804.01 311 591.11 0.0003
2016-11-10 2016-09-30 13F A10 NETWORKS COM 002121101 4,142 -1,921 -31.68 45 12.50 0.0000
2016-08-12 2016-06-30 13F A10 NETWORKS COM 002121101 6,063 -41,481 -87.25 40 -85.77 0.0000
2016-05-13 2016-03-31 13F A10 NETWORKS COM 002121101 47,544 36,309 323.18 281 279.73 0.0003
2016-02-12 2015-12-31 13F A10 NETWORKS COM 002121101 11,235 9,917 752.43 74 825.00 0.0001
2015-11-13 2015-09-30 13F A10 NETWORKS COM 002121101 1,318 -4,520 -77.42 8 -78.38 0.0000
2015-08-13 2015-06-30 13F A10 NETWORKS COM 002121101 5,838 32 0.55 37 48.00 0.0000
2015-05-14 2015-03-31 13F A10 NETWORKS COM 002121101 5,806 -35,863 -86.07 25 -86.26 0.0000
2015-02-17 2014-12-31 13F A10 NETWORKS COM 002121101 41,669 40,791 4,645.90 182 2,175.00 0.0002
2014-11-14 2014-09-30 13F A10 NETWORKS COM 002121101 878 769 705.50 8 700.00 0.0000
2014-08-14 2014-06-30 13F A10 NETWORKS COM 002121101 109 109 1 0.0000
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.