Willdan Group, Inc.
US ˙ NasdaqGM ˙ US96924N1000

SecurityWLDN / Willdan Group, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership31,579 shares
Latest Disclosed Value $ 2,417,688
Citadel Advisors Llc ownership in WLDN / Willdan Group, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 31,579 shares of Willdan Group, Inc. (US:WLDN) valued at $2,417,688 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 76,558 shares of Willdan Group, Inc.. This represents a change in shares of -58.75% during the quarter. The current value of the position is $3,069,795 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (WLDN) in the form of stock options. The firm currently holds call options representing 35,200 of underlying shares valued at $2,694,912 USD and put options representing 15,800 of underlying shares valued at $1,209,648 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.

WLDN / Willdan Group, 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)
2026-05-15 2026-03-31 13F WILLDAN GROUP COM 96924N100 31,579 -44,979 -58.75 2,418 -69.54 0.0003
2026-02-17 2025-12-31 13F WILLDAN GROUP COM 96924N100 76,558 -109,316 -58.81 7,936 -55.84 0.0012
2025-11-14 2025-09-30 13F WILLDAN GROUP COM 96924N100 185,874 77,503 71.52 17,972 165.31 0.0027
2025-08-14 2025-06-30 13F WILLDAN GROUP COM 96924N100 108,371 74,623 221.12 6,774 393.01 0.0012
2025-05-15 2025-03-31 13F WILLDAN GROUP COM 96924N100 33,748 5,606 19.92 1,374 28.29 0.0003
2025-02-14 2024-12-31 13F WILLDAN GROUP COM 96924N100 28,142 -70,448 -71.46 1,072 -73.47 0.0002
2024-11-14 2024-09-30 13F WILLDAN GROUP COM 96924N100 98,590 -562 -0.57 4,037 41.15 0.0008
2024-08-14 2024-06-30 13F WILLDAN GROUP COM 96924N100 99,152 51,956 110.09 2,861 109.06 0.0006
2024-05-15 2024-03-31 13F WILLDAN GROUP COM 96924N100 47,196 13,814 41.38 1,368 90.79 0.0003
2024-02-14 2023-12-31 13F WILLDAN GROUP COM 96924N100 33,382 -72 -0.22 718 4.98 0.0001
2023-11-14 2023-09-30 13F WILLDAN GROUP COM 96924N100 33,454 -1,592 -4.54 683 1.79 0.0001
2023-08-14 2023-06-30 13F WILLDAN GROUP COM 96924N100 35,046 -21,767 -38.31 671 -24.35 0.0001
2023-05-15 2023-03-31 13F WILLDAN GROUP COM 96924N100 56,813 8,902 18.58 887 3.74 0.0002
2023-02-14 2022-12-31 13F WILLDAN GROUP COM 96924N100 47,911 21,965 84.66 855 122.66 0.0002
2022-11-14 2022-09-30 13F WILLDAN GROUP COM 96924N100 25,946 17,089 192.94 384 57.38 0.0001
2022-08-15 2022-06-30 13F WILLDAN GROUP COM 96924N100 8,857 -7,837 -46.95 244 -52.44 0.0001
2022-05-16 2022-03-31 13F WILLDAN GROUP COM 96924N100 16,694 -18,838 -53.02 513 -58.99 0.0001
2022-02-14 2021-12-31 13F WILLDAN GROUP COM 96924N100 35,532 365 1.04 1,251 0.00 0.0003
2021-11-15 2021-09-30 13F WILLDAN GROUP Cmn 96924N100 35,167 -30,870 -46.75 1,251 -49.66 0.0003
2021-08-16 2021-06-30 13F WILLDAN GROUP COM 96924N100 66,037 5,902 9.81 2,485 0.69 0.0006
2021-05-21 2021-03-31 13F/A-1 WILLDAN GROUP COM 96924N100 60,135 60,135 2,468 0.0006
2021-05-17 2021-03-31 13F WILLDAN GROUP COM 96924N100 60,135 60,135 2,468 0.0006
2020-11-16 2020-09-30 13F WILLDAN GROUP Cmn 96924N100 0 -9,078 -100.00 0 -100.00
2020-08-14 2020-06-30 13F WILLDAN GROUP Cmn 96924N100 9,078 -6,068 -40.06 227 -29.72 0.0001
2020-05-15 2020-03-31 13F WILLDAN GROUP Cmn 96924N100 15,146 8,068 113.99 323 43.56 0.0001
2020-02-14 2019-12-31 13F WILLDAN GROUP Cmn 96924N100 7,078 -24 -0.34 225 -9.64 0.0001
2019-11-14 2019-09-30 13F WILLDAN GROUP Cmn 96924N100 7,102 403 6.02 249 -0.40 0.0001
2019-08-14 2019-06-30 13F WILLDAN GROUP Cmn 96924N100 6,699 6,699 250 0.0001
2019-05-15 2019-03-31 13F WILLDAN GROUP Cmn 96924N100 0 -14,047 -100.00 0 -100.00
2019-02-14 2018-12-31 13F WILLDAN GROUP Cmn 96924N100 14,047 7,906 128.74 491 134.93 0.0003
2018-11-13 2018-09-30 13F WILLDAN GROUP Cmn 96924N100 6,141 6,141 209 0.0001
2015-11-16 2015-09-30 13F WILLDAN GROUP Cmn 96924N100 0 -25,454 -100.00 0 -100.00
2015-08-14 2015-06-30 13F WILLDAN GROUP Cmn 96924N100 25,454 9,261 57.19 284 10.94 0.0002
2015-05-15 2015-03-31 13F WILLDAN GROUP Cmn 96924N100 16,193 7,914 95.59 256 128.57 0.0003
2015-02-17 2014-12-31 13F WILLDAN GROUP Cmn 96924N100 8,279 8,279 112 0.0001
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
(%)
2026-05-15 2026-03-31 13F WILLDAN GROUP COM Call 35,200 -39.21 2,695 -55.11 n/a n/a n/a
2026-02-17 2025-12-31 13F WILLDAN GROUP COM Call 57,900 41.91 6,002 52.16 n/a n/a n/a
2025-11-14 2025-09-30 13F WILLDAN GROUP COM Call 40,800 303.96 3,945 525.04 n/a n/a n/a
2025-08-14 2025-06-30 13F WILLDAN GROUP COM Call 10,100 -18.55 631 25.20 n/a n/a n/a
2025-05-15 2025-03-31 13F WILLDAN GROUP COM Call 12,400 0.81 505 7.69 n/a n/a n/a
2025-02-14 2024-12-31 13F WILLDAN GROUP COM Call 12,300 9.82 469 2.18 n/a n/a n/a
2024-11-14 2024-09-30 13F WILLDAN GROUP COM Call 11,200 -2.61 459 38.37 n/a n/a n/a
2024-08-14 2024-06-30 13F WILLDAN GROUP COM Call 11,500 26.37 332 25.86 n/a n/a n/a
2024-05-15 2024-03-31 13F WILLDAN GROUP COM Call 9,100 264.00 264 396.23 n/a n/a n/a
2024-02-14 2023-12-31 13F WILLDAN GROUP COM Call 2,500 -26.47 54 -23.19 n/a n/a n/a
2023-11-14 2023-09-30 13F WILLDAN GROUP COM Call 3,400 61.90 69 72.50 n/a n/a n/a
2023-08-14 2023-06-30 13F WILLDAN GROUP COM Call 2,100 -8.70 40 14.29 n/a n/a n/a
2023-05-15 2023-03-31 13F WILLDAN GROUP COM Call 2,300 -68.49 36 -73.08 n/a n/a n/a
2023-02-14 2022-12-31 13F WILLDAN GROUP COM Call 7,300 130 n/a n/a n/a
2022-03-11 2021-09-30 13F/A WILLDAN GROUP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-15 2021-09-30 13F WILLDAN GROUP COM Call 0 0 n/a n/a n/a
2021-08-16 2021-06-30 13F WILLDAN GROUP COM Call 23,900 -8.78 900 -16.36 n/a n/a n/a
2021-05-21 2021-03-31 13F/A WILLDAN GROUP COM Call 26,200 170.10 1,076 166.34 n/a n/a n/a
2021-05-17 2021-03-31 13F WILLDAN GROUP COM Call 26,200 1,076 n/a n/a n/a
2021-02-16 2020-12-31 13F WILLDAN GROUP COM Call 9,700 404 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
(%)
2026-05-15 2026-03-31 13F WILLDAN GROUP COM Put 15,800 81.61 1,210 34.18 n/a n/a n/a
2026-02-17 2025-12-31 13F WILLDAN GROUP COM Put 8,700 -69.47 902 -67.30 n/a n/a n/a
2025-11-14 2025-09-30 13F WILLDAN GROUP COM Put 28,500 2,756 n/a n/a n/a
2025-08-14 2025-06-30 13F WILLDAN GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F WILLDAN GROUP COM Put 2,000 -64.29 81 -61.97 n/a n/a n/a
2025-02-14 2024-12-31 13F WILLDAN GROUP COM Put 5,600 33.33 213 24.56 n/a n/a n/a
2024-11-14 2024-09-30 13F WILLDAN GROUP COM Put 4,200 -44.00 172 -20.83 n/a n/a n/a
2024-08-14 2024-06-30 13F WILLDAN GROUP COM Put 7,500 2.74 216 2.37 n/a n/a n/a
2024-05-15 2024-03-31 13F WILLDAN GROUP COM Put 7,300 7,200.00 212 10,450.00 n/a n/a n/a
2024-02-14 2023-12-31 13F WILLDAN GROUP COM Put 100 -94.74 2 -94.74 n/a n/a n/a
2023-11-14 2023-09-30 13F WILLDAN GROUP COM Put 1,900 850.00 39 1,166.67 n/a n/a n/a
2023-08-14 2023-06-30 13F WILLDAN GROUP COM Put 200 4 n/a n/a n/a
2023-05-15 2023-03-31 13F WILLDAN GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-02-14 2022-12-31 13F WILLDAN GROUP COM Put 400 7 n/a n/a n/a
2021-08-16 2021-06-30 13F WILLDAN GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-05-21 2021-03-31 13F/A WILLDAN GROUP COM Put 6,300 259 n/a n/a n/a
2021-05-17 2021-03-31 13F WILLDAN GROUP COM Put 6,300 259 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.