Donaldson Company, Inc.
US ˙ NYSE ˙ US2576511099

SecurityDCI / Donaldson Company, Inc.
InstitutionMairs & Power Inc
Latest Disclosed Ownership499,374 shares
Latest Disclosed Value $ 42,381,944
Mairs & Power Inc reports 10.93% decrease in ownership of DCI / Donaldson Company, Inc.

On May 13, 2026 - Mairs & Power Inc filed a 13F-HR form disclosing ownership of 499,374 shares of Donaldson Company, Inc. (US:DCI) valued at $42,381,871 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 560,653 shares of Donaldson Company, Inc.. This represents a change in shares of -10.93% during the quarter. The current value of the position is $42,566,640 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 DONALDSON COM 257651109 499,374 -61,279 -10.93 42,382 -14.74 0.4331
2026-02-17 2025-12-31 13F DONALDSON COM 257651109 560,653 -44,786 -7.40 49,707 0.31 0.4784
2025-11-14 2025-09-30 13F DONALDSON COM 257651109 605,439 -224,066 -27.01 49,555 -13.86 0.4658
2025-08-14 2025-06-30 13F DONALDSON COM 257651109 829,505 -290,644 -25.95 57,526 -23.42 0.5679
2025-05-15 2025-03-31 13F DONALDSON COM 257651109 1,120,149 -189,826 -14.49 75,117 -14.86 0.7816
2025-02-14 2024-12-31 13F DONALDSON COM 257651109 1,309,975 -61,987 -4.52 88,227 -12.75 0.8535
2024-11-14 2024-09-30 13F DONALDSON COM 257651109 1,371,962 -126,858 -8.46 101,114 -5.73 0.9511
2024-08-14 2024-06-30 13F DONALDSON COM 257651109 1,498,820 -102,211 -6.38 107,256 -10.29 1.0363
2024-05-15 2024-03-31 13F DONALDSON COM 257651109 1,601,031 -287,650 -15.23 119,565 -3.13 1.1577
2024-02-14 2023-12-31 13F DONALDSON COM 257651109 1,888,681 -56,279 -2.89 123,425 6.40 1.3005
2023-11-14 2023-09-30 13F DONALDSON COM 257651109 1,944,960 -295,595 -13.19 115,997 -17.18 1.3613
2023-08-14 2023-06-30 13F DONALDSON COM 257651109 2,240,555 -192,388 -7.91 140,057 -11.90 1.5233
2023-05-15 2023-03-31 13F DONALDSON COM 257651109 2,432,943 -373,630 -13.31 158,968 -3.79 1.8342
2023-02-14 2022-12-31 13F DONALDSON COM 257651109 2,806,573 -207,236 -6.88 165,223 11.86 1.9889
2022-11-14 2022-09-30 13F DONALDSON COM 257651109 3,013,809 -100,198 -3.22 147,707 -1.47 1.8635
2022-08-15 2022-06-30 13F DONALDSON COM 257651109 3,114,007 -195,195 -5.90 149,908 -12.77 1.7966
2022-05-16 2022-03-31 13F DONALDSON COM 257651109 3,309,202 -16,608 -0.50 171,847 -12.81 1.7311
2022-02-14 2021-12-31 13F DONALDSON COM 257651109 3,325,810 -11,309 -0.34 197,087 2.87 1.8254
2021-11-15 2021-09-30 13F DONALDSON COM 257651109 3,337,119 -90 -0.00 191,584 -9.64 1.9168
2021-08-16 2021-06-30 13F DONALDSON COM 257651109 3,337,209 -41,360 -1.22 212,013 7.90 2.0953
2021-05-14 2021-03-31 13F DONALDSON COM 257651109 3,378,569 -135,266 -3.85 196,498 0.07 2.0630
2021-02-16 2020-12-31 13F DONALDSON COM 257651109 3,513,835 -65,436 -1.83 196,353 18.18 2.1819
2020-11-16 2020-09-30 13F DONALDSON COM 257651109 3,579,271 -109,211 -2.96 166,150 -3.17 2.0751
2020-08-14 2020-06-30 13F DONALDSON COM 257651109 3,688,482 -661,605 -15.21 171,588 2.11 2.2419
2020-05-15 2020-03-31 13F DONALDSON COM 257651109 4,350,087 -64,097 -1.45 168,044 -33.93 2.4525
2020-02-14 2019-12-31 13F Donaldson COM 257651109 4,414,184 -314,059 -6.64 254,345 3.29 2.8895
2019-11-14 2019-09-30 13F Donaldson COM 257651109 4,728,243 -272,588 -5.45 246,247 -3.18 2.9763
2019-08-14 2019-06-30 13F Donaldson COM 257651109 5,000,831 -46,771 -0.93 254,342 0.66 3.0517
2019-05-15 2019-03-31 13F Donaldson COM 257651109 5,047,602 53,870 1.08 252,683 16.62 3.0687
2019-02-14 2018-12-31 13F Donaldson COM 257651109 4,993,732 -95,101 -1.87 216,678 -26.92 2.9230
2018-11-14 2018-09-30 13F Donaldson COM 257651109 5,088,833 -311,180 -5.76 296,475 21.68 3.4518
2018-08-14 2018-06-30 13F Donaldson COM 257651109 5,400,013 -121,246 -2.20 243,649 -2.04 3.0216
2018-05-15 2018-03-31 13F Donaldson COM 257651109 5,521,259 68,475 1.26 248,733 -6.81 3.0702
2018-02-14 2017-12-31 13F Donaldson COM 257651109 5,452,784 115,490 2.16 266,914 8.86 3.0947
2017-11-14 2017-09-30 13F Donaldson COM 257651109 5,337,294 78,111 1.49 245,195 2.38 2.9436
2017-08-14 2017-06-30 13F Donaldson COM 257651109 5,259,183 2,983 0.06 239,503 0.10 2.8952
2017-05-15 2017-03-31 13F Donaldson COM 257651109 5,256,200 -84,376 -1.58 239,262 6.47 2.9311
2017-02-14 2016-12-31 13F Donaldson COM 257651109 5,340,576 -262,097 -4.68 224,731 7.45 2.8854
2016-11-14 2016-09-30 13F Donaldson COM 257651109 5,602,673 -63,454 -1.12 209,148 7.43 2.7568
2016-08-15 2016-06-30 13F Donaldson COM 257651109 5,666,127 215,421 3.95 194,688 11.93 2.6280
2016-05-16 2016-03-31 13F Donaldson COM 257651109 5,450,706 95,558 1.78 173,932 13.33 2.4721
2016-02-16 2015-12-31 13F Donaldson COM 257651109 5,355,148 50,973 0.96 153,479 3.05 2.3005
2015-11-16 2015-09-30 13F Donaldson COM 257651109 5,304,175 87,730 1.68 148,941 -20.25 2.3280
2015-08-14 2015-06-30 13F Donaldson COM 257651109 5,216,445 25,287 0.49 186,749 -4.60 2.6435
2015-05-15 2015-03-31 13F Donaldson COM 257651109 5,191,158 116,945 2.30 195,759 -0.13 2.6927
2015-02-17 2014-12-31 13F Donaldson COM 257651109 5,074,213 380,074 8.10 196,017 2.78 2.7200
2014-11-14 2014-09-30 13F Donaldson COM 257651109 4,694,139 187,654 4.16 190,723 0.00 2.7833
2014-08-14 2014-06-30 13F Donaldson COM 257651109 4,506,485 257,680 6.06 190,714 5.86 2.7044
2014-05-15 2014-03-31 13F Donaldson COM 257651109 4,248,805 -4,532 -0.11 180,149 -2.54 2.6695
2014-02-14 2013-12-31 13F Donaldson COM 257651109 4,253,337 116,688 2.82 184,850 17.19 2.8437
2013-11-14 2013-09-30 13F Donaldson COM 257651109 4,136,649 217,695 5.55 157,730 12.87 2.7254
2013-08-14 2013-06-30 13F Donaldson COM 257651109 3,918,954 3,918,954 139,750 2.6712
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.