Mesa Laboratories, Inc.
US ˙ NasdaqGS ˙ US59064R1095

SecurityMLAB / Mesa Laboratories, Inc.
InstitutionNorthern Trust Corp
Latest Disclosed Ownership69,264 shares
Latest Disclosed Value $ 6,124,324
Northern Trust Corp reports 5.50% increase in ownership of MLAB / Mesa Laboratories, Inc.

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 69,264 shares of Mesa Laboratories, Inc. (US:MLAB) valued at $6,124,323 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 65,651 shares of Mesa Laboratories, Inc.. This represents a change in shares of 5.50% during the quarter. The current value of the position is $7,558,780 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)
2026-05-14 2026-03-31 13F MESA LABS COM 59064R109 69,264 3,613 5.50 6,124 18.84 0.0002
2026-02-17 2025-12-31 13F MESA LABS COM 59064R109 65,651 -6,315 -8.77 5,154 6.86 0.0001
2025-11-14 2025-09-30 13F MESA LABS COM 59064R109 71,966 -20,766 -22.39 4,822 -44.81 0.0001
2025-08-13 2025-06-30 13F MESA LABS COM 59064R109 92,732 10,288 12.48 8,737 -10.68 0.0012
2025-05-13 2025-03-31 13F MESA LABS COM 59064R109 82,444 -11,345 -12.10 9,783 -20.90 0.0015
2025-02-14 2024-12-31 13F MESA LABS COM 59064R109 93,789 1,825 1.98 12,368 3.56 0.0018
2024-11-13 2024-09-30 13F MESA LABS COM 59064R109 91,964 1,616 1.79 11,942 52.34 0.0020
2024-08-14 2024-06-30 13F MESA LABS COM 59064R109 90,348 -1,685 -1.83 7,839 -22.37 0.0013
2024-05-14 2024-03-31 13F MESA LABS COM 59064R109 92,033 10,515 12.90 10,099 18.24 0.0017
2024-02-13 2023-12-31 13F MESA LABS COM 59064R109 81,518 -13,385 -14.10 8,541 -14.35 0.0015
2023-11-13 2023-09-30 13F MESA LABS COM 59064R109 94,903 1,910 2.05 9,971 -16.55 0.0019
2023-08-11 2023-06-30 13F MESA LABS COM 59064R109 92,993 6,213 7.16 11,950 -21.20 0.0023
2023-05-15 2023-03-31 13F MESA LABS COM 59064R109 86,780 2,291 2.71 15,163 7.98 0.0030
2023-02-13 2022-12-31 13F MESA LABS COM 59064R109 84,489 21 0.02 14,043 18.04 0.0029
2022-11-14 2022-09-30 13F MESA LABS COM 59064R109 84,468 -5,058 -5.65 11,896 -34.84 0.0027
2022-08-12 2022-06-30 13F MESA LABS COM 59064R109 89,526 6,509 7.84 18,257 -13.72 0.0039
2022-05-13 2022-03-31 13F MESA LABS COM 59064R109 83,017 1,135 1.39 21,160 -21.24 0.0037
2022-02-08 2021-12-31 13F MESA LABS COM 59064R109 81,882 -1,543 -1.85 26,865 6.51 0.0044
2021-11-15 2021-09-30 13F MESA LABS COM 59064R109 83,425 -5,719 -6.42 25,224 4.35 0.0045
2021-08-13 2021-06-30 13F MESA LABS COM 59064R109 89,144 11,629 15.00 24,173 28.07 0.0043
2021-05-12 2021-03-31 13F MESA LABS COM 59064R109 77,515 480 0.62 18,875 -14.52 0.0035
2021-02-11 2020-12-31 13F MESA LABS COM 59064R109 77,035 -2,931 -3.67 22,082 8.39 0.0043
2020-11-16 2020-09-30 13F MESA LABS COM 59064R109 79,966 5,134 6.86 20,372 25.57 0.0045
2020-08-14 2020-06-30 13F MESA LABS COM 59064R109 74,832 287 0.39 16,224 -3.73 0.0038
2020-05-14 2020-03-31 13F MESA LABS COM 59064R109 74,545 -1,542 -2.03 16,853 -11.19 0.0048
2020-02-14 2019-12-31 13F MESA LABS COM 59064R109 76,087 540 0.71 18,976 5.64 0.0042
2019-11-13 2019-09-30 13F MESA LABS COM 59064R109 75,547 6,109 8.80 17,963 5.88 0.0043
2019-08-13 2019-06-30 13F MESA LABS COM 59064R109 69,438 3,905 5.96 16,966 12.32 0.0040
2019-05-13 2019-03-31 13F MESA LABS COM 59064R109 65,533 6,539 11.08 15,105 22.87 0.0037
2019-02-12 2018-12-31 13F MESA LABS COM 59064R109 58,994 9,764 19.83 12,293 34.53 0.0034
2018-11-14 2018-09-30 13F MESA LABS COM 59064R109 49,230 1,063 2.21 9,138 -10.12 0.0022
2018-09-18 2018-06-30 13F/A-1 MESA LABS COM 59064R109 48,167 3,222 7.17 10,167 52.38 0.0026
2018-08-14 2018-06-30 13F MESA LABS COM 59064R109 48,415 3,470 10,219
2018-05-09 2018-03-31 13F MESA LABS COM 59064R109 44,945 -273 -0.60 6,672 18.70 0.0017
2018-02-14 2017-12-31 13F MESA LABS COM 59064R109 45,218 -232 -0.51 5,621 -17.17 0.0014
2017-11-13 2017-09-30 13F MESA LABS COM 59064R109 45,450 177 0.39 6,786 4.59 0.0018
2017-08-11 2017-06-30 13F MESA LABS COM 59064R109 45,273 2,843 6.70 6,488 24.60 0.0018
2017-05-12 2017-03-31 13F MESA LABS COM 59064R109 42,430 1 0.00 5,207 -0.02 0.0015
2017-02-13 2016-12-31 13F MESA LABS COM 59064R109 42,429 3,293 8.41 5,208 16.38 0.0016
2016-11-09 2016-09-30 13F MESA LABS COM 59064R109 39,136 209 0.54 4,475 -6.54 0.0014
2016-08-12 2016-06-30 13F MESA LABS COM 59064R109 38,927 1,328 3.53 4,788 32.16 0.0016
2016-08-19 2016-03-31 13F/A-1 MESA LABS COM 59064R109 37,599 142 0.38 3,623 -2.79 0.0012
2016-05-13 2016-03-31 13F MESA LABS COM 59064R109 37,599 3,623
2016-02-12 2015-12-31 13F MESA LABS COM 59064R109 37,457 1,152 3.17 3,727 -7.86 0.0012
2015-11-12 2015-09-30 13F MESA LABS COM 59064R109 36,305 36,305 0.00 4,045 0.0013
2015-08-13 2015-06-30 13F MESA LABS COM 59064R109 0 -36,734 -100.00 0 -100.00
2015-05-14 2015-03-31 13F MESA LABS COM 59064R109 36,734 -58 -0.16 2,653 -6.72 0.0008
2015-02-12 2014-12-31 13F MESA LABS COM 59064R109 36,792 -68 -0.18 2,844 33.52 0.0009
2014-11-13 2014-09-30 13F MESA LABS COM 59064R109 36,860 818 2.27 2,130 -29.61 0.0007
2014-08-14 2014-06-30 13F MESA LABS COM 59064R109 36,042 -4,014 -10.02 3,026 -16.29 0.0009
2014-05-14 2014-03-31 13F MESA LABS COM 59064R109 40,056 -2,670 -6.25 3,615 7.65 0.0011
2014-02-21 2013-12-31 13F/A-1 MESA LABS COM 59064R109 42,726 331 0.78 3,358 17.13 0.0011
2014-02-12 2013-12-31 13F MESA LABS COM 59064R109 42,726 3,358
2013-11-13 2013-09-30 13F MESA LABS COM 59064R109 42,395 1,016 2.46 2,867 27.99 0.0010
2013-08-09 2013-06-30 13F MESA LABS COM 59064R109 41,379 41,379 2,240 0.0008
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.