SEI Investments Company
MX ˙ BMV ˙ US7841171033
SecurityMX:SEIC / SEI Investments Company
InstitutionRhumbline Advisers
Latest Disclosed Ownership309,487 shares
Latest Disclosed Value $ 24,285,383
Rhumbline Advisers reports 0.05% increase in ownership of SEIC / SEI Investments Company

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 309,487 shares of SEI Investments Company (MX:SEIC) valued at $24,285,383 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 309,335 shares of SEI Investments Company. This represents a change in shares of 0.05% 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 CO COM COM 784117103 309,487 152 0.05 24,285 -4.28 0.0208
2026-02-13 2025-12-31 13F SEI INVTS CO COM COM 784117103 309,335 -16,905 -5.18 25,372 -8.35 0.0205
2025-11-06 2025-09-30 13F SEI INVTS CO COM COM 784117103 326,240 9,859 3.12 27,681 -2.63 0.0222
2025-08-12 2025-06-30 13F SEI INVTS CO COM COM 784117103 316,381 -20,173 -5.99 28,430 8.81 0.0243
2025-05-29 2025-03-31 13F/A-1 SEI INVTS CO COM COM 784117103 336,554 -1,438 -0.43 26,127 -6.28 0.0244
2025-04-08 2025-03-31 13F SEI INVTS CO COM COM 784117103 336,554 -1,438 26,127 0.0244
2025-05-29 2024-12-31 13F/A-1 SEI INVTS CO COM COM 784117103 337,992 -1,419 -0.42 27,878 18.71 0.0249
2025-01-30 2024-12-31 13F SEI INVTS CO COM COM 784117103 337,992 -1,419 27,878 0.0249
2024-11-12 2024-09-30 13F SEI INVTS CO COM COM 784117103 339,411 -5,517 -1.60 23,484 5.24 0.0212
2024-08-01 2024-06-30 13F SEI INVTS CO COM COM 784117103 344,928 553 0.16 22,313 -9.88 0.0210
2024-05-09 2024-03-31 13F SEI INVTS CO COM COM 784117103 344,375 -2,169 -0.63 24,761 12.43 0.0238
2024-02-08 2023-12-31 13F SEI INVTS CO COM COM 784117103 346,544 3,463 1.01 22,023 6.58 0.0231
2023-11-09 2023-09-30 13F SEI INVTS CO COM COM 784117103 343,081 -5,066 -1.46 20,664 -0.45 0.0240
2023-08-08 2023-06-30 13F SEI INVTS CO COM COM 784117103 348,147 20,687 6.32 20,757 115,211.11 0.0232
2023-05-11 2023-03-31 13F SEI INVTS CO COM COM 784117103 327,460 -4,289 -1.29 19 -99.91 0.0233
2023-02-14 2022-12-31 13F SEI INVTS CO COM COM 784117103 331,749 3,290 1.00 19,341 20.05 0.0260
2022-11-10 2022-09-30 13F SEI INVTS CO COM COM 784117103 328,459 4,000 1.23 16,111 -8.08 0.0240
2022-08-11 2022-06-30 13F SEI INVTS CO COM COM 784117103 324,459 18,721 6.12 17,527 -4.79 0.0256
2022-05-12 2022-03-31 13F SEI INVTS CO COM COM 784117103 305,738 -6,674 -2.14 18,408 -3.31 0.0237
2022-02-10 2021-12-31 13F SEI INVTS CO COM COM 784117103 312,412 1,079 0.35 19,038 3.12 0.0233
2021-11-12 2021-09-30 13F SEI INVTS CO COM COM 784117103 311,333 -28,922 -8.50 18,462 -12.44 0.0250
2021-08-05 2021-06-30 13F SEI INVTS CO COM COM 784117103 340,255 -5,961 -1.72 21,086 -0.04 0.0277
2021-05-06 2021-03-31 13F SEI INVTS CO COM COM 784117103 346,216 -6,113 -1.74 21,095 4.18 0.0287
2021-02-10 2020-12-31 13F SEI INVTS CO COM COM 784117103 352,329 -24,938 -6.61 20,248 5.82 0.0279
2020-11-12 2020-09-30 13F SEI INVTS CO COM COM 784117103 377,267 -8,822 -2.28 19,135 -9.86 0.0300
2020-08-13 2020-06-30 13F SEI INVTS CO COM COM 784117103 386,089 -8,507 -2.16 21,227 16.08 0.0354
2020-05-06 2020-03-31 13F SEI INVTS CO COM COM 784117103 394,596 31,628 8.71 18,286 -23.06 0.0383
2020-02-05 2019-12-31 13F SEI INVTS CO COM COM 784117103 362,968 4,204 1.17 23,767 11.80 0.0397
2019-10-23 2019-09-30 13F SEI INVTS CO COM COM 784117103 358,764 -5,803 -1.59 21,259 3.95 0.0388
2019-08-14 2019-06-30 13F SEI INVTS CO COM COM 784117103 364,567 -9,973 -2.66 20,452 4.51 0.0384
2019-05-01 2019-03-31 13F SEI INVTS CO COM COM 784117103 374,540 -475 -0.13 19,570 12.95 0.0379
2019-01-31 2018-12-31 13F SEI INVTS CO COM COM 784117103 375,015 84,086 28.90 17,326 -2.53 0.0377
2018-11-07 2018-09-30 13F SEI INVTS CO COM COM 784117103 290,929 -7,382 -2.47 17,776 -4.69 0.0343
2018-08-06 2018-06-30 13F SEI INVTS CO COM COM 784117103 298,311 931 0.31 18,650 -16.28 0.0376
2018-05-02 2018-03-31 13F SEI INVTS CO COM COM 784117103 297,380 -18,802 -5.95 22,277 -1.95 0.0465
2018-02-09 2017-12-31 13F SEI INVTS CO COM COM 784117103 316,182 8,672 2.82 22,721 21.00 0.0461
2017-11-06 2017-09-30 13F SEI INVTS CO COM COM 784117103 307,510 16,528 5.68 18,777 19.99 0.0408
2017-08-02 2017-06-30 13F SEI INVTS CO COM COM 784117103 290,982 6,848 2.41 15,649 9.19 0.0357
2017-05-02 2017-03-31 13F SEI INVTS CO COM COM 784117103 284,134 -11,912 -4.02 14,332 -1.92 0.0335
2017-01-27 2016-12-31 13F SEI INVTS CO COM COM 784117103 296,046 13,235 4.68 14,613 13.29 0.0370
2016-11-08 2016-09-30 13F SEI INVTS CO COM COM 784117103 282,811 4,944 1.78 12,899 -3.51 0.0355
2016-08-11 2016-06-30 13F SEI INVTS CO COM COM 784117103 277,867 -2,307 -0.82 13,368 10.84 0.0396
2016-05-02 2016-03-31 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 280,174 27,860 11.04 12,061 -8.77 0.0374
2016-02-03 2015-12-31 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 252,314 2,330 0.93 13,221 9.65 0.0425
2015-11-04 2015-09-30 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 249,984 -18,204 -6.79 12,057 -8.30 0.0410
2015-08-04 2015-06-30 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 268,188 29,167 12.20 13,149 24.78 0.0419
2015-05-12 2015-03-31 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 239,021 -5,572 -2.28 10,538 7.60 0.0304
2015-02-06 2014-12-31 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 244,593 -1,085 -0.44 9,794 10.24 0.0285
2014-11-12 2014-09-30 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 245,678 -6,123 -2.43 8,884 7.66 0.0267
2014-08-06 2014-06-30 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 251,801 -29,863 -10.60 8,252 -12.83 0.0242
2014-05-06 2014-03-31 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 281,664 -9,743 -3.34 9,467 -6.46 0.0281
2014-02-03 2013-12-31 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 291,407 -23,624 -7.50 10,121 3.93 0.0299
2013-11-05 2013-09-30 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 315,031 70,697 28.93 9,738 40.20 0.0302
2013-08-07 2013-06-30 13F SEI INVESTMENTS COMPANY COMMON COM 784117103 244,334 244,334 6,946 0.0223
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.