폼팩터, Inc.
US ˙ NasdaqGS ˙ US3463751087

SecurityFORM / FormFactor, Inc.
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership35,569 shares
Latest Disclosed Value $ 3,449,659
Janus Henderson Group Plc reports 8.21% increase in ownership of FORM / FormFactor, Inc.

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 35,569 shares of FormFactor, Inc. (US:FORM) valued at $3,449,837 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 32,869 shares of FormFactor, Inc.. This represents a change in shares of 8.21% during the quarter. The current value of the position is $4,503,213 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)
2026-05-18 2026-03-31 13F/A-1 FORMFACTOR COM 346375108 35,569 2,700 8.21 3,450 88.26 0.0006
2026-05-15 2026-03-31 13F FORMFACTOR COM 346375108 35,569 2,700 3,450 0.0006
2026-02-17 2025-12-31 13F FORMFACTOR COM 346375108 32,869 0 0.00 1,833 53.05 0.0008
2025-11-14 2025-09-30 13F FORMFACTOR COM 346375108 32,869 0 0.00 1,197 5.93 0.0005
2025-08-14 2025-06-30 13F FORMFACTOR COM 346375108 32,869 0 0.00 1,130 20.21 0.0006
2025-05-15 2025-03-31 13F FORMFACTOR COM 346375108 32,869 -4,200 -11.33 940 -42.30 0.0005
2025-02-14 2024-12-31 13F FORMFACTOR COM 346375108 37,069 0 0.00 1,630 -4.46 0.0008
2024-11-14 2024-09-30 13F FORMFACTOR COM 346375108 37,069 0 0.00 1,706 -24.02 0.0009
2024-08-14 2024-06-30 13F FORMFACTOR COM 346375108 37,069 -398 -1.06 2,244 31.38 0.0012
2024-05-15 2024-03-31 13F FORMFACTOR COM 346375108 37,467 2 0.01 1,709 9.28 0.0009
2024-02-14 2023-12-31 13F FORMFACTOR COM 346375108 37,465 -62 -0.17 1,563 19.22 0.0009
2023-11-14 2023-09-30 13F FORMFACTOR COM 346375108 37,527 6 0.02 1,311 2.18 0.0009
2023-08-14 2023-06-30 13F FORMFACTOR COM 346375108 37,521 -41 -0.11 1,283 7.36 0.0008
2023-05-15 2023-03-31 13F FORMFACTOR COM 346375108 37,562 -53,944 -58.95 1,195 -41.25 0.0008
2023-02-14 2022-12-31 13F FORMFACTOR COM 346375108 91,506 -313,932 -77.43 2,034 -79.97 0.0015
2023-01-13 2022-09-30 13F/A-1 FORMFACTOR COM 346375108 405,438 -157,053 -27.92 10,156 -53.38 0.0076
2022-11-14 2022-09-30 13F FORMFACTOR COM 346375108 405,438 -157,053 10,156 0.0026
2022-08-15 2022-06-30 13F FORMFACTOR COM 346375108 562,491 -20,399 -3.50 21,786 -11.07 0.0150
2022-05-16 2022-03-31 13F FORMFACTOR COM 346375108 582,890 -20,991 -3.48 24,499 -11.26 0.0118
2022-02-14 2021-12-31 13F FORMFACTOR COM 346375108 603,881 221,355 57.87 27,609 93.34 0.0115
2021-11-16 2021-09-30 13F FORMFACTOR COM 346375108 382,526 291,677 321.06 14,280 331.16 0.0062
2021-08-16 2021-06-30 13F FORMFACTOR COM 346375108 90,849 -6,646 -6.82 3,312 -24.69 0.0014
2021-05-17 2021-03-31 13F FORMFACTOR COM 346375108 97,495 39,127 67.04 4,398 75.15 0.0020
2021-02-16 2020-12-31 13F FORMFACTOR COM 346375108 58,368 -5,698 -8.89 2,511 57.23 0.0012
2020-11-16 2020-09-30 13F FORMFACTOR COM 346375108 64,066 -1,068 -1.64 1,597 -16.39 0.0008
2020-08-14 2020-06-30 13F FORMFACTOR COM 346375108 65,134 65,134 1,910 0.0011
2020-05-14 2020-03-31 13F FORMFACTOR COM 346375108 0 -56,753 -100.00 0 -100.00
2020-02-18 2019-12-31 13F FORMFACTOR COM 346375108 56,753 8,511 17.64 1,474 63.96 0.0008
2019-11-14 2019-09-30 13F FORMFACTOR COM 346375108 48,242 6,292 15.00 899 36.83 0.0005
2019-07-31 2019-06-30 13F FORMFACTOR COM 346375108 41,950 15,573 59.04 657 54.95 0.0004
2019-04-30 2019-03-31 13F FORMFACTOR COM 346375108 26,377 8,114 44.43 424 64.98 0.0002
2019-02-06 2018-12-31 13F FORMFACTOR COM 346375108 18,263 -5,975 -24.65 257 -22.82 0.0002
2018-11-09 2018-09-30 13F FORMFACTOR COM 346375108 24,238 13,076 117.15 333 125.00 0.0002
2018-08-10 2018-06-30 13F FORMFACTOR COM 346375108 11,162 11,162 148 0.0001
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.