Acadian Asset Management Inc.
US ˙ NYSE ˙ US10948W1036

SecurityAAMI / Acadian Asset Management Inc.
InstitutionD. E. Shaw & Co., Inc.
ManagerDE Shaw
Latest Disclosed Ownership56,410 shares
Latest Disclosed Value $ 3,069,832
D. E. Shaw & Co., Inc. reports 50.98% decrease in ownership of AAMI / Acadian Asset Management Inc.

On May 15, 2026 - D. E. Shaw & Co., Inc. filed a 13F-HR form disclosing ownership of 56,410 shares of Acadian Asset Management Inc. (US:AAMI) valued at $3,069,832 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 115,086 shares of Acadian Asset Management Inc.. This represents a change in shares of -50.98% during the quarter. The current value of the position is $4,076,187 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)
2026-05-15 2026-03-31 13F ACADIAN ASSET MANAGEMENT COM 10948W103 56,410 -58,676 -50.98 3,070 -43.26 0.0018
2026-02-17 2025-12-31 13F ACADIAN ASSET MANAGEMENT COM 10948W103 115,086 26,991 30.64 5,409 27.51 0.0030
2025-11-14 2025-09-30 13F ACADIAN ASSET MANAGEMENT COM 10948W103 88,095 -10,454 -10.61 4,243 22.18 0.0024
2025-08-14 2025-06-30 13F ACADIAN ASSET MANAGEMENT COM 10948W103 98,549 -13,608 -12.13 3,473 19.72 0.0025
2025-05-15 2025-03-31 13F ACADIAN ASSET MANAGEMENT COM 10948W103 112,157 33,345 42.31 2,900 39.76 0.0026
2025-02-14 2024-12-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 78,812 -52,331 -39.90 2,076 -37.71 0.0015
2024-11-14 2024-09-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 131,143 -57,559 -30.50 3,331 -20.37 0.0029
2024-08-14 2024-06-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 188,702 46,099 32.33 4,184 28.43 0.0039
2024-05-15 2024-03-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 142,603 -38,519 -21.27 3,257 -6.14 0.0028
2024-02-14 2023-12-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 181,122 75,543 71.55 3,470 69.52 0.0030
2023-11-14 2023-09-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 105,579 57,335 118.84 2,047 102.67 0.0021
2023-08-14 2023-06-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 48,244 24,059 99.48 1,011 77.19 0.0010
2023-05-15 2023-03-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 24,185 -165 -0.68 570 13.77 0.0006
2023-02-14 2022-12-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 24,350 -3,488 -12.53 501 20.72 0.0006
2022-11-14 2022-09-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 27,838 27,838 415 0.0005
2022-08-15 2022-06-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 0 -9,623 -100.00 0 -100.00
2022-05-16 2022-03-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 9,623 9,623 233 0.0002
2021-02-16 2020-12-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 0 -24,183 -100.00 0 -100.00
2020-11-16 2020-09-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 24,183 -121,376 -83.39 312 -82.80 0.0003
2020-08-14 2020-06-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 145,559 -197,988 -57.63 1,814 -17.36 0.0022
2020-05-15 2020-03-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 343,547 -251,742 -42.29 2,195 -63.92 0.0034
2020-02-14 2019-12-31 13F BRIGHTSPHERE INVT GROUP COM 10948W103 595,289 104,671 21.33 6,084 25.13 0.0070
2019-11-14 2019-09-30 13F BRIGHTSPHERE INVT GROUP COM 10948W103 490,618 294,944 150.73 4,862 117.83 0.0060
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.