ADTRAN Holdings, Inc.
US ˙ NasdaqGS ˙ US00486H1059

SecurityADTN / ADTRAN Holdings, Inc.
InstitutionQuantbot Technologies LP
Latest Disclosed Ownership56,800 shares
Latest Disclosed Value $ 714,544
Quantbot Technologies LP reports 425.39% increase in ownership of ADTN / ADTRAN Holdings, Inc.

On May 13, 2026 - Quantbot Technologies LP filed a 13F-HR form disclosing ownership of 56,800 shares of ADTRAN Holdings, Inc. (US:ADTN) valued at $714,544 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 10,811 shares of ADTRAN Holdings, Inc.. This represents a change in shares of 425.39% during the quarter. The current value of the position is $997,408 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)
2026-05-13 2026-03-31 13F ADTRAN HOLDINGS COM 00486H105 56,800 45,989 425.39 715 667.74 0.0292
2026-02-10 2025-12-31 13F ADTRAN HOLDINGS COM 00486H105 10,811 -115,679 -91.45 94 -92.16 0.0031
2025-11-12 2025-09-30 13F ADTRAN HOLDINGS COM 00486H105 126,490 106,110 520.66 1,186 551.65 0.0323
2025-08-13 2025-06-30 13F ADTRAN HOLDINGS COM 00486H105 20,380 -107,209 -84.03 183 -83.63 0.0047
2025-05-13 2025-03-31 13F ADTRAN HOLDINGS COM 00486H105 127,589 112,644 753.72 1,113 796.77 0.0354
2025-02-11 2024-12-31 13F ADTRAN HOLDINGS COM 00486H105 14,945 7,636 104.47 124 188.37 0.0045
2024-11-13 2024-09-30 13F ADTRAN HOLDINGS COM 00486H105 7,309 -41,527 -85.03 43 -83.20 0.0017
2024-08-09 2024-06-30 13F ADTRAN HOLDINGS COM 00486H105 48,836 25,555 109.77 257 103.17 0.0124
2024-05-06 2024-03-31 13F ADTRAN HOLDINGS COM 00486H105 23,281 -57,214 -71.08 127 -78.64 0.0071
2024-02-14 2023-12-31 13F ADTRAN HOLDINGS COM 00486H105 80,495 32,803 68.78 591 50.51 0.0343
2023-11-07 2023-09-30 13F ADTRAN HOLDINGS COM 00486H105 47,692 47,692 393 0.0264
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.