Columbia Banking System, Inc.
US ˙ NasdaqGS ˙ US1972361026

SecurityCOLB / Columbia Banking System, Inc.
InstitutionAmalgamated Bank
Latest Disclosed Ownership134,193 shares
Latest Disclosed Value $ 3,681
Amalgamated Bank reports 0.96% decrease in ownership of COLB / Columbia Banking System, Inc.

On May 8, 2026 - Amalgamated Bank filed a 13F-HR form disclosing ownership of 134,193 shares of Columbia Banking System, Inc. (US:COLB) valued at $3,680,914 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 135,496 shares of Columbia Banking System, Inc.. This represents a change in shares of -0.96% during the quarter. The current value of the position is $3,836,578 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)
2026-05-08 2026-03-31 13F COLUMBIA BANKING SYSTEM COM 197236102 134,193 -1,303 -0.96 4 0.00 0.0282
2026-02-05 2025-12-31 13F COLUMBIA BANKING SYSTEM COM 197236102 135,496 -874 -0.64 4 0.00 0.0273
2025-10-29 2025-09-30 13F COLUMBIA BANKING SYSTEM COM 197236102 136,370 40,435 42.15 4 50.00 0.0251
2025-08-04 2025-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 95,935 -1,108 -1.14 2 0.00 0.0173
2025-04-25 2025-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 97,043 -2,663 -2.67 2 0.00 0.0207
2025-02-04 2024-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 99,706 -176 -0.18 3 0.00 0.0221
2024-10-30 2024-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 99,882 -31,281 -23.85 3 0.00 0.0215
2024-08-12 2024-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 131,163 -11,140 -7.83 3 0.00 0.0222
2024-04-23 2024-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 142,303 10,817 8.23 3 -33.33 0.0236
2024-02-06 2023-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 131,486 -6,400 -4.64 4 50.00 0.0280
2023-11-08 2023-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 137,886 1,917 1.41 3 0.00 0.0238
2023-08-11 2023-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 135,969 -6,878 -4.81 3 -33.33 0.0223
2023-05-02 2023-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 142,847 106,956 298.00 3 200.00 0.0261
2023-02-10 2022-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 35,891 244 0.68 1 -99.90 0.0096
2022-11-09 2022-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 35,647 500 1.42 1,030 2.28 0.0099
2022-08-15 2022-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 35,147 -73 -0.21 1,007 -11.43 0.0094
2022-08-25 2022-03-31 13F/A-1 COLUMBIA BANKING SYSTEMS COM 197236102 35,220 -1,430 -3.90 1,137 -5.17 0.0088
2022-06-30 2022-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 35,220 -1,430 1,137 0.0090
2022-02-15 2021-12-31 13F/A-1 COLUMBIA BANKING SYSTEMS COM 197236102 36,650 -7 -0.02 1,199 -13.93 0.0088
2022-02-15 2021-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 36,650 -7 1,199 0.0088
2021-10-29 2021-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 36,657 1,571 4.48 1,393 2.96 0.0118
2021-08-16 2021-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 35,086 28,670 446.85 1,353 390.22 0.0108
2021-05-13 2021-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 6,416 -426 -6.23 276 12.20 0.0103
2021-02-12 2020-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 6,842 6,842 246 0.0093
2020-08-10 2020-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 0 -11,780 -100.00 0 -100.00
2020-05-13 2020-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 11,780 -335 -2.77 316 -35.90 0.0077
2020-02-13 2019-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 12,115 784 6.92 493 17.94 0.0091
2019-11-13 2019-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 11,331 -252 -2.18 418 -0.24 0.0088
2019-08-14 2019-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 11,583 761 7.03 419 18.36 0.0098
2019-05-15 2019-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 10,822 373 3.57 354 -6.60 0.0086
2019-02-15 2018-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 10,449 -26 -0.25 379 -6.65 0.0107
2018-11-14 2018-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 10,475 -111 -1.05 406 -6.24 0.0100
2018-07-18 2018-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 10,586 440 4.34 433 1.64 0.0106
2018-05-22 2018-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 10,146 -119 -1.16 426 -4.48 0.0113
2018-02-13 2017-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 10,265 2,421 30.86 446 35.15 0.0121
2017-11-09 2017-09-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 7,844 -101 -1.27 330 4.10 0.0103
2017-08-10 2017-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 7,945 84 1.07 317 3.26 0.0104
2017-05-12 2017-03-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 7,861 10 0.13 307 -12.54 0.0153
2017-02-14 2016-12-31 13F COLUMBIA BANKING SYSTEMS COM 197236102 7,851 931 13.45 351 55.31 0.0159
2016-11-15 2016-09-30 13F/A-1 COLUMBIA BANKING SYSTEMS COM 197236102 6,920 12 0.17 226 4.15 0.0131
2016-08-16 2016-06-30 13F COLUMBIA BANKING SYSTEMS COM 197236102 6,908 6,908 217 0.0126
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.