SEI Investments Company
MX ˙ BMV ˙ US7841171033
SecurityMX:SEIC / SEI Investments Company
InstitutionM&t Bank Corp
Latest Disclosed Ownership4,958 shares
Latest Disclosed Value $ 389,054
M&t Bank Corp reports 12.10% increase in ownership of SEIC / SEI Investments Company

On May 12, 2026 - M&t Bank Corp filed a 13F-HR form disclosing ownership of 4,958 shares of SEI Investments Company (MX:SEIC) valued at $389,054 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on January 30, 2026 disclosing 4,423 shares of SEI Investments Company. This represents a change in shares of 12.10% during the quarter.

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)
2026-05-12 2026-03-31 13F SEI INVTS COM 784117103 4,958 535 12.10 389 7.46 0.0003
2026-01-30 2025-12-31 13F/A-1 SEI INVTS COM 784117103 4,423 4,423 363 0.0012
2026-01-28 2025-12-31 13F SEI INVTS COM 784117103 45,822 45,822 6,567 0.0039
2025-11-14 2025-09-30 13F SEI INVTS COM 784117103 0 -3,217 -100.00 0 -100.00
2025-08-13 2025-06-30 13F SEI INVTS COM 784117103 3,217 341 11.86 289 29.60 0.0010
2025-04-30 2025-03-31 13F SEI INVTS COM 784117103 2,876 -1,860 -39.27 223 -42.82 0.0008
2025-02-06 2024-12-31 13F SEI INVTS COM 784117103 4,736 -245 -4.92 391 13.37 0.0013
2024-11-19 2024-09-30 13F/A-1 SEI INVTS COM 784117103 4,981 -4,604 -48.03 345 -44.52 0.0011
2024-11-15 2024-09-30 13F SEI INVTS COM 784117103 4,981 -4,604 345 0.0002
2024-07-31 2024-06-30 13F SEI INVTS COM 784117103 9,585 -609 -5.97 620 -15.30 0.0021
2024-05-07 2024-03-31 13F SEI INVTS COM 784117103 10,194 -860 -7.78 733 4.27 0.0026
2024-02-06 2023-12-31 13F SEI INVTS COM 784117103 11,054 -1,865 -14.44 703 -9.77 0.0026
2023-11-02 2023-09-30 13F SEI INVTS COM 784117103 12,919 -149 -1.14 778 -0.13 0.0031
2023-08-09 2023-06-30 13F SEI INVTS COM 784117103 13,068 -1,358 -9.41 779 -6.14 0.0029
2023-05-11 2023-03-31 13F SEI INVTS COM 784117103 14,426 -3,278 -18.52 830 -19.65 0.0032
2023-02-13 2022-12-31 13F/A-1 SEI INVTS COM 784117103 17,704 896 5.33 1,033 25.06 0.0042
2023-02-13 2022-12-31 13F SBA COMMUNICATIONS CORP CL A 784117103 17,871 1,063 1,160 0.0047
2022-11-17 2022-09-30 13F/A-1 SEI INVTS COM 784117103 16,808 227 1.37 826 4.29 0.0037
2022-11-14 2022-09-30 13F SEI INVTS COM 784117103 16,808 227 717 0.0006
2022-08-05 2022-06-30 13F SEI INVTS COM 784117103 16,581 1,111 7.18 792 -15.02 0.0037
2022-05-09 2022-03-31 13F SEI INVTS COM 784117103 15,470 4,128 36.40 932 34.88 0.0041
2022-02-07 2021-12-31 13F SEI INVTS COM 784117103 11,342 -207 -1.79 691 0.88 0.0029
2021-10-28 2021-09-30 13F SEI INVTS COM 784117103 11,549 154 1.35 685 -2.97 0.0031
2021-08-13 2021-06-30 13F SEI INVTS COM 784117103 11,395 237 2.12 706 3.82 0.0031
2021-05-06 2021-03-31 13F SEI INVTS COM 784117103 11,158 -822 -6.86 680 -1.31 0.0029
2021-02-12 2020-12-31 13F SEI INVTS COM 784117103 11,980 89 0.75 689 14.26 0.0030
2020-11-06 2020-09-30 13F SEI INVTS COM 784117103 11,891 -1,092 -8.41 603 -15.43 0.0030
2020-07-29 2020-06-30 13F SEI INVTS COM 784117103 12,983 110 0.85 713 19.43 0.0038
2020-05-14 2020-03-31 13F SEI INVESTMENTS COM 784117103 12,873 -6,556 -33.74 597 -53.07 0.0035
2020-02-07 2019-12-31 13F SEI INVESTMENTS COM 784117103 19,429 -635 -3.16 1,272 7.07 0.0060
2019-11-12 2019-09-30 13F SEI INVESTMENTS COM 784117103 20,064 152 0.76 1,188 6.45 0.0059
2019-08-12 2019-06-30 13F SEI INVESTMENTS COM 784117103 19,912 -1,845 -8.48 1,116 -1.93 0.0058
2019-05-15 2019-03-31 13F SEI INVESTMENTS COM 784117103 21,757 578 2.73 1,138 16.24 0.0060
2019-02-01 2018-12-31 13F SEI INVESTMENTS COM 784117103 21,179 341 1.64 979 -23.16 0.0056
2018-11-09 2018-09-30 13F SEI INVESTMENTS COM 784117103 20,838 4,954 31.19 1,274 28.30 0.0064
2018-08-10 2018-06-30 13F SEI INVESTMENTS COM 784117103 15,884 -296 -1.83 993 -18.07 0.0053
2018-05-04 2018-03-31 13F SEI INVESTMENTS COM 784117103 16,180 1,237 8.28 1,212 12.85 0.0065
2018-02-06 2017-12-31 13F SEI INVESTMENTS COM 784117103 14,943 -391 -2.55 1,074 14.74 0.0056
2017-11-13 2017-09-30 13F SEI INVESTMENTS COM 784117103 15,334 -46 -0.30 936 13.04 0.0051
2017-08-11 2017-06-30 13F SEI INVESTMENTS COM 784117103 15,380 515 3.46 828 10.40 0.0049
2017-05-10 2017-03-31 13F SEI INVESTMENTS COM 784117103 14,865 -2,139 -12.58 750 -10.71 0.0045
2017-02-14 2016-12-31 13F SEI INVESTMENTS COM 784117103 17,004 -108 -0.63 840 7.69 0.0052
2016-11-04 2016-09-30 13F SEI INVESTMENTS COM 784117103 17,112 -7,513 -30.51 780 -34.18 0.0050
2016-08-04 2016-06-30 13F SEI INVESTMENTS COM 784117103 24,625 4,671 23.41 1,185 37.79 0.0080
2016-05-11 2016-03-31 13F SEI INVESTMENTS COM 784117103 19,954 575 2.97 860 -15.35 0.0058
2016-02-12 2015-12-31 13F SEI INVESTMENTS COM 784117103 19,379 209 1.09 1,016 9.96 0.0067
2015-11-13 2015-09-30 13F SEI INVESTMENTS COM 784117103 19,170 -2,891 -13.10 924 -14.60 0.0063
2015-08-14 2015-06-30 13F SEI INVESTMENTS COM 784117103 22,061 -4,622 -17.32 1,082 -8.07 0.0065
2015-05-14 2015-03-31 13F SEI INVESTMENTS COM 784117103 26,683 -136 -0.51 1,177 9.59 0.0073
2015-02-12 2014-12-31 13F SEI INVESTMENTS COM 784117103 26,819 3,811 16.56 1,074 29.09 0.0067
2014-11-14 2014-09-30 13F SEI INVESTMENTS COM 784117103 23,008 22,833 13,047.43 832 13,766.67 0.0058
2014-08-13 2014-06-30 13F SEI CORP COM COMMON 784117103 175 0 0.00 6 0.00 0.0003
2014-05-14 2014-03-31 13F SEI CORP COM COMMON STOCK 784117103 175 0 0.00 6 0.00 0.0002
2014-02-12 2013-12-31 13F SEI CORP COM COMMON STOCK 784117103 175 0 0.00 6 20.00 0.0003
2013-11-13 2013-09-30 13F SEI CORP COM COMMON STOCK 784117103 175 0 0.00 5 0.00 0.0002
2013-07-30 2013-06-30 13F SEI CORP COM COMMON STOCK 784117103 175 175 5 0.0002
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.