Westamerica Bancorporation
US ˙ NasdaqGS ˙ US9570901036

SecurityWABC / Westamerica Bancorporation
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership944,699 shares
Latest Disclosed Value $ 49,264,998
Dimensional Fund Advisors Lp reports 5.25% increase in ownership of WABC / Westamerica Bancorporation

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 944,699 shares of Westamerica Bancorporation (US:WABC) valued at $49,266,053 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 897,572 shares of Westamerica Bancorporation. This represents a change in shares of 5.25% during the quarter. The current value of the position is $53,451,069 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)
2026-05-07 2026-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 944,699 47,127 5.25 49,265 14.75 0.0022
2026-02-12 2025-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 897,572 3,378 0.38 42,932 -3.96 0.0090
2025-11-12 2025-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 894,194 6,473 0.73 44,700 3.95 0.0096
2025-08-12 2025-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 887,721 2,641 0.30 43,002 -4.03 0.0100
2025-05-13 2025-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 885,080 9,780 1.12 44,810 -2.42 0.0111
2025-02-13 2024-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 875,300 9,928 1.15 45,919 7.37 0.0110
2024-11-07 2024-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 865,372 3,974 0.46 42,766 2.31 0.0104
2024-08-09 2024-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 861,398 41,841 5.11 41,801 4.35 0.0109
2024-05-10 2024-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 819,557 36,824 4.70 40,060 -9.28 0.0108
2024-02-07 2023-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 782,733 21,547 2.83 44,155 34.13 0.0129
2023-11-09 2023-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 761,186 24,612 3.34 32,921 16.69 0.0108
2023-08-09 2023-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 736,574 10,152 1.40 28,212 -12.33 0.0090
2023-05-12 2023-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 726,422 40,598 5.92 32,180 80,350.00 0.0108
2023-02-09 2022-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 685,824 -4,732 -0.69 40 -99.89 0.0120
2022-11-10 2022-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 690,556 7,605 1.11 36,109 -5.01 0.0139
2022-08-12 2022-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 682,951 6,914 1.02 38,013 -7.06 0.0136
2022-05-13 2022-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 676,037 8,955 1.34 40,900 6.21 0.0126
2022-02-09 2021-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 667,082 1,374 0.21 38,510 2.82 0.0116
2021-11-12 2021-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 665,708 -10,450 -1.55 37,453 -4.55 0.0121
2021-08-12 2021-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 676,158 -3,000 -0.44 39,237 -7.98 0.0124
2021-05-14 2021-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 679,158 -32,725 -4.60 42,639 8.33 0.0141
2021-03-08 2020-12-31 13F/A-2 WESTAMERICA BANCORPORATION COM 957090103 711,883 -12,543 -1.73 39,359 -0.04 0.0142
2021-02-11 2020-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 711,883 -12,543 39,359 14,214.3788
2020-11-12 2020-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 724,426 -19,785 -2.66 39,373 -7.86 0.0167
2020-08-13 2020-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 744,211 -10,918 -1.45 42,730 -3.73 0.0188
2020-05-14 2020-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 755,129 4,397 0.59 44,387 -12.76 0.0231
2020-02-14 2019-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 750,732 1,584 0.21 50,878 9.22 0.0185
2019-11-12 2019-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 749,148 2,478 0.33 46,583 1.26 0.0181
2019-08-13 2019-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 746,670 4,319 0.58 46,002 0.27 0.0179
2019-08-12 2019-03-31 13F/A-2 WESTAMERICA BANCORPORATION COM 957090103 742,351 -73 -0.01 45,878 10.98 0.0183
2019-05-10 2019-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 742,351 -73 45,878
2019-02-26 2018-12-31 13F/A-1 WESTAMERICA BANCORPORATION COM 957090103 742,424 19,762 2.73 41,339 -4.91 0.0187
2019-02-13 2018-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 742,424 19,762 41,339
2018-11-13 2018-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 722,662 14,225 2.01 43,475 8.59 0.0165
2018-08-10 2018-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 708,437 44,309 6.67 40,035 3.79 0.0160
2018-05-11 2018-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 664,128 -1,551 -0.23 38,573 -2.70 0.0161
2018-02-12 2017-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 665,679 -1,700 -0.25 39,642 -0.23 0.0164
2017-11-13 2017-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 667,379 -2,992 -0.45 39,735 5.77 0.0174
2017-08-11 2017-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 670,371 -1,960 -0.29 37,569 0.09 0.0173
2017-05-12 2017-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 672,331 -5,166 -0.76 37,537 -11.96 0.0179
2017-02-09 2016-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 677,497 -1,857 -0.27 42,635 23.35 0.0213
2016-11-10 2016-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 679,354 -2,918 -0.43 34,565 2.85 0.0187
2016-08-09 2016-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 682,272 -934 -0.14 33,608 0.99 0.0193
2016-05-13 2016-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 683,206 -74,901 -9.88 33,280 -6.10 0.0199
2016-02-10 2015-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 758,107 51,672 7.31 35,443 12.90 0.0221
2015-11-13 2015-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 706,435 117,597 19.97 31,394 5.26 0.0206
2015-08-14 2015-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 588,838 23,339 4.13 29,825 22.06 0.0183
2015-05-14 2015-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 565,499 85,517 17.82 24,435 3.85 0.0154
2015-02-06 2014-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 479,982 59,840 14.24 23,529 20.38 0.0155
2014-11-13 2014-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 420,142 -1,298 -0.31 19,545 -11.29 0.0138
2014-08-08 2014-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 421,440 -1,100 -0.26 22,033 -3.58 0.0153
2014-05-14 2014-03-31 13F WESTAMERICA BANCORPORATION COM 957090103 422,540 17,442 4.31 22,850 -0.10 0.0171
2014-02-12 2013-12-31 13F WESTAMERICA BANCORPORATION COM 957090103 405,098 18,144 4.69 22,872 18.84 0.0178
2013-11-13 2013-09-30 13F WESTAMERICA BANCORPORATION COM 957090103 386,954 18,614 5.05 19,246 14.36 0.0167
2013-08-15 2013-06-30 13F WESTAMERICA BANCORPORATION COM 957090103 368,340 368,340 16,830 0.0158
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.