ADTRAN Holdings, Inc.
US ˙ NasdaqGS ˙ US00486H1059

SecurityADTN / ADTRAN Holdings, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership18,427 shares
Latest Disclosed Value $ 231,812
Citigroup Inc reports 35.25% increase in ownership of ADTN / ADTRAN Holdings, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 18,427 shares of ADTRAN Holdings, Inc. (US:ADTN) valued at $231,812 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 13,624 shares of ADTRAN Holdings, Inc.. This represents a change in shares of 35.25% during the quarter. The current value of the position is $323,578 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 ADTRAN HOLDINGS COM 00486H105 18,427 4,803 35.25 232 95.76 0.0000
2026-02-13 2025-12-31 13F ADTRAN HOLDINGS COM 00486H105 13,624 -5,843 -30.01 118 -35.16 0.0001
2025-11-10 2025-09-30 13F ADTRAN HOLDINGS COM 00486H105 19,467 -21,368 -52.33 183 -50.27 0.0001
2025-08-11 2025-06-30 13F ADTRAN HOLDINGS COM 00486H105 40,835 -115,784 -73.93 366 -73.19 0.0002
2025-05-12 2025-03-31 13F ADTRAN HOLDINGS COM 00486H105 156,619 87,998 128.24 1,366 139.05 0.0007
2025-02-12 2024-12-31 13F ADTRAN HOLDINGS COM 00486H105 68,621 -3,300 -4.59 572 34.04 0.0003
2024-11-12 2024-09-30 13F ADTRAN HOLDINGS COM 00486H105 71,921 -27,012 -27.30 426 -18.08 0.0002
2024-08-12 2024-06-30 13F ADTRAN HOLDINGS COM 00486H105 98,933 36,292 57.94 520 52.94 0.0003
2024-05-10 2024-03-31 13F ADTRAN HOLDINGS COM 00486H105 62,641 2,873 4.81 341 -22.37 0.0002
2024-02-09 2023-12-31 13F ADTRAN HOLDINGS COM 00486H105 59,768 24,536 69.64 439 51.56 0.0003
2023-12-06 2023-09-30 13F/A-1 ADTRAN HOLDINGS COM 00486H105 35,232 -28,053 -44.33 290 -56.61 0.0002
2023-11-09 2023-09-30 13F ADTRAN HOLDINGS COM 00486H105 35,232 -28,053 290 0.0001
2023-08-10 2023-06-30 13F ADTRAN HOLDINGS COM 00486H105 63,285 26,334 71.27 666 13.65 0.0004
2023-05-11 2023-03-31 13F ADTRAN HOLDINGS COM 00486H105 36,951 -11,244 -23.33 586 -35.25 0.0004
2023-02-09 2022-12-31 13F ADTRAN HOLDINGS COM 00486H105 48,195 -2,087 -4.15 906 -8.12 0.0007
2022-11-10 2022-09-30 13F ADTRAN HOLDINGS COM 00486H105 50,282 50,282 985 0.0007
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.