Trinseo PLC - Ordinary Shares, par value $0.01 per share (TSE) Institutional Ownership

13F Institutional Holders and Ownership History from Q3 2019 to Q4 2025

Type / Class
Equity / Ordinary Shares, par value $0.01 per share
Symbol
TSE on NYSE
Shares outstanding
35,464,436
Price per share
$0.50
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
26,848,081
Total reported value
$60,426,503
% of total 13F portfolios
0%
Share change
-813,804
Value change
-$2,561,222
Number of holders
74
Price from insider filings
$0.50
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of Trinseo PLC - Ordinary Shares, par value $0.01 per share (TSE) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
CastleKnight Master Fund LP 7.8% $8,022,055 2,766,226 CastleKnight Master Fund LP 30 Jun 2025
BlackRock, Inc. 6.3% $8,456,719 2,255,125 BlackRock, Inc. 30 Jun 2025

As of 30 Sep 2025, 74 institutional investors reported holding 26,848,081 shares of Trinseo PLC - Ordinary Shares, par value $0.01 per share (TSE). This represents 76% of the company’s total 35,464,436 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of Trinseo PLC - Ordinary Shares, par value $0.01 per share (TSE) together control 74% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
M&G PLC 22% 7,625,044 0% 0.08% $15,250,088
Nut Tree Capital Management, LP 9.9% 3,500,000 0% 1.9% $8,225,000
CastleKnight Management LP 7% 2,466,826 -11% 0.31% $5,797,041
BlackRock, Inc. 6.7% 2,369,672 +5.1% 0% $5,568,730
Owl Creek Asset Management, L.P. 4.7% 1,669,952 0% 0.45% $3,924,387
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 4.2% 1,505,068 +56% 0% $3,536,910
BRIGHTLINE CAPITAL MANAGEMENT, LLC 3% 1,060,000 +3.7% 1% $2,491,000
ICON ADVISERS INC/CO 2.8% 1,000,000 +33% 0.51% $2,350,000
GEODE CAPITAL MANAGEMENT, LLC 2.4% 841,828 +2.3% 0% $1,978,715
VANGUARD GROUP INC 2.1% 755,643 -30% 0% $1,775,761
MORGAN STANLEY 1.3% 454,287 -2.9% 0% $1,067,574
STATE STREET CORP 1.2% 423,786 +11% 0% $995,897
BANK OF AMERICA CORP /DE/ 1% 363,641 +20% 0% $854,556
RENAISSANCE TECHNOLOGIES LLC 0.89% 314,700 +13% 0% $739,545
LAKEWOOD CAPITAL MANAGEMENT, LP 0.79% 281,279 0% 0.05% $661,006
NORTHERN TRUST CORP 0.76% 268,689 +1.1% 0% $631,419
ROYAL BANK OF CANADA 0.64% 227,821 -3.7% 0% $536,000
UBS Group AG 0.56% 199,804 +4.9% 0% $469,539
Alta Fundamental Advisers LLC 0.43% 152,974 0.17% $359,489
D. E. Shaw & Co., Inc. 0.42% 147,316 -53% 0% $346,193
Invesco Ltd. 0.37% 131,802 -32% 0% $309,735
GOLDMAN SACHS GROUP INC 0.36% 125,993 +7.8% 0% $296,084
DIMENSIONAL FUND ADVISORS LP 0.33% 117,669 -0.39% 0% $276,580
Voleon Capital Management LP 0.23% 82,074 0% $192,874
Bank of New York Mellon Corp 0.23% 81,402 +0.01% 0% $191,294

Institutional Holders of Trinseo PLC - Ordinary Shares, par value $0.01 per share (TSE) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q4 1,294 $644 +$529 $0.50 3
2025 Q3 26,848,081 $60,426,503 -$2,561,222 $2.35 74
2025 Q2 27,680,017 $85,444,543 +$6,908,226 $3.12 80
2025 Q1 25,205,020 $95,192,408 +$227,708 $3.68 85
2024 Q4 24,965,599 $126,559,235 +$8,302,489 $5.10 95
2024 Q3 22,908,998 $116,234,027 -$3,240,258 $5.11 71
2024 Q2 25,261,519 $55,987,559 -$9,396,897 $2.31 95
2024 Q1 27,408,421 $105,280,091 -$21,098,784 $3.78 104
2023 Q4 29,143,643 $241,188,653 -$5,907,974 $8.37 126
2023 Q3 29,752,666 $241,775,134 -$41,807,613 $8.17 144
2023 Q2 32,802,961 $418,132,080 -$12,498,617 $12.67 140
2023 Q1 33,318,012 $695,818,411 +$11,139,887 $20.85 165
2022 Q4 32,790,143 $747,004,231 +$30,441,354 $22.71 178
2022 Q3 31,874,971 $581,417,571 -$50,356,911 $18.32 163
2022 Q2 34,023,738 $1,305,500,527 -$11,045,976 $38.46 183
2022 Q1 34,508,974 $1,654,900,596 -$28,237,350 $47.92 181
2021 Q4 35,066,439 $1,836,288,499 +$1,805,342,295 $52.46 171
2021 Q3 232,117 $12,490,120 +$12,441,532 $53.97 14
2021 Q2 900 $53,856 $59.84 1
2021 Q1 900 $57,303 -$1,000 $63.67 1
2020 Q4 916 $47,089 $56.86 2
2020 Q3 900 $23,076 $25.64 1
2020 Q2 900 $19,944 +$19,944 $22.16 1
2019 Q4 0 $0 -$32,728 $0.50 0
2019 Q3 762 $32,728 +$32,728 $42.95 1