v3.26.3
Investments (Tables)
9 Months Ended
Sep. 30, 2026
Investments, Debt and Equity Securities [Abstract]  
Schedule of Fixed Maturity and Short-Term Investments
The Company’s fixed maturity and short-term investments are as follows:

September 30, 2026
($ in thousands)
Amortized CostGross Unrealized GainsGross Unrealized LossesFair Value
Fixed maturities:
U.S. government treasuries$365,667 $— $(14,989)$350,678 
U.S. states, territories and municipalities9,462 — (223)9,239 
Non-U.S. sovereign governments and supranationals96,034 345 (4,029)92,350 
Corporate1,891,295 4,448 (66,339)1,829,404 
Residential mortgage-backed securities - Agency366,158 4 (19,785)346,377 
Residential mortgage-backed securities - Non-agency100,297 95 (3,958)96,434 
Commercial mortgage-backed securities - Non-agency87,238 3 (2,759)84,482 
Other asset-backed securities351,536 396 (2,971)348,961 
Total fixed maturities3,267,687 5,291 (115,053)3,157,925 
Short-term investments
423,363 709 (26)424,046 
Total$3,691,050 $6,000 $(115,079)$3,581,971 

December 31, 2025
($ in thousands)
Amortized CostGross Unrealized GainsGross Unrealized LossesFair Value
Fixed maturities:
U.S. government treasuries$795,780 $4,782 $(2,728)$797,834 
U.S. states, territories and municipalities12,924 89 (53)12,960 
Non-U.S. sovereign governments and supranationals108,296 3,102 (537)110,861 
Corporate1,557,582 29,899 (3,337)1,584,144 
Residential mortgage-backed securities - Agency370,516 4,419 (9,285)365,650 
Residential mortgage-backed securities - Non-agency33,052 319 (826)32,545 
Commercial mortgage-backed securities - Non-agency94,223 835 (360)94,698 
Other asset-backed securities238,567 1,401 (117)239,851 
Total fixed maturities3,210,940 44,846 (17,243)3,238,543 
Short-term investments
200,052 419 (12)200,459 
 Total
$3,410,992 $45,265 $(17,255)$3,439,002 
Schedule of Contractual Maturities of Fixed Maturity Securities
The following table presents contractual maturities of fixed maturity securities. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

September 30, 2026
($ in thousands)
Amortized CostFair Value
Due less than one year
$47,870 $47,814 
Due after one through five years
1,418,639 1,384,030 
Due after five through ten years
814,853 774,640 
Due after ten years
81,096 75,187 
Mortgage-backed securities
553,693 527,293 
Asset-backed securities
351,536 348,961 
Total
$3,267,687 $3,157,925 
Schedule of Investments in Two Sigma Funds
The Company owns the following interest in each of the Two Sigma Funds:

September 30, 2026
Two Sigma FundsAbbreviation%
Two Sigma Spectrum Portfolio, LLCSTV12.3 %
Two Sigma Equity Spectrum Portfolio, LLCESTV9.6 %
Two Sigma Absolute Return Portfolio, LLCATV0.2 %
Two Sigma Futures Portfolio, LLCFTV6.5 %
Two Sigma Horizon Portfolio, LLCHTV5.2 %
Two Sigma Navigator Portfolio, LLCNTV5.8 %
Two Sigma Kuiper Portfolio, LLCKTV5.1 %
The Company’s investments in Two Sigma Funds are as follows:

($ in thousands)
September 30, 2026December 31, 2025
Two Sigma FundsCostNet Unrealized Gains (Losses)Fair ValueCostNet Unrealized Gains (Losses)Fair Value
Two Sigma Spectrum Portfolio, LLC$48,246 $19,105 $67,351 $500,616 $131,996 $632,612 
Two Sigma Equity Spectrum Portfolio, LLC769,374 280,203 1,049,577 187,718 49,906 237,624 
Two Sigma Absolute Return Portfolio, LLC9,789 3,210 12,999 93,092 8,882 101,974 
Two Sigma Futures Portfolio, LLC236,926 49,433 286,359 192,064 44,998 237,062 
Two Sigma Horizon Portfolio, LLC266,392 22,480 288,872 241,090 4,585 245,675 
Two Sigma Navigator Portfolio, LLC125,927 27,418 153,345 110,577 (9,585)100,992 
Two Sigma Kuiper Portfolio, LLC15,331 45 15,376 30,406 1,313 31,719 
Total
$1,471,985 $401,894 $1,873,879 $1,355,563 $232,095 $1,587,658 
Schedule of Certain Investments of Two Sigma Funds
The following table summarizes certain investments of the Two Sigma Funds where TS Hamilton Fund’s proportionate share of the fair value of the investment represents more than 5% of TS Hamilton Fund’s members’ equity:

September 30, 2026
($ in thousands)
Principal / Shares (1)
Fair
Value (1)
% of Members’ Equity
BlackRock Liquidity Funds T-Fund Portfolio155,787 $155,787 5.9 %
Invesco Treasury Portfolio Money Market Fund167,517 $167,517 6.3 %
U.S. Treasury Securities, 0.0000% - 5.1250%, due 10/1/2026 - 5/15/20562,230,441 $2,166,051 81.6 %
U.S. Treasury Securities, 3.5000% - 5.1250%, due 1/31/2027 - 8/15/2056(201,398)$(190,608)(7.2)%
(1) Values represent TS Hamilton Fund’s proportionate share of the aggregate of the Two Sigma Funds’ total holdings.
Schedule of Realized and Unrealized Gains (Losses) on Investments and Net Investment Income (Loss)
The components of total net realized and unrealized gains (losses) on investments and net investment income (loss) are as follows:

Three Months EndedNine Months Ended
September 30,September 30,
($ in thousands)
2026202520262025
Net realized and unrealized gains (losses) on investments:
Net realized gains (losses) on investments$166,722 $109,355 $554,472 $424,142 
Change in net unrealized gains (losses) on investments41,804 5,781 32,986 147,822 
Net realized and unrealized gains (losses) on investments208,526 115,136 587,458 571,964 
Net investment income (loss):
Fixed maturities36,065 30,070 104,850 82,674 
Short-term investments3 155 22 453 
TS Hamilton Fund1,507 3,243 5,091 7,837 
Cash and cash equivalents5,002 3,986 13,491 12,576 
Other781 (575)1,184 611 
Interest and other43,358 36,879 124,638 104,151 
Management fees(16,432)(13,889)(46,544)(40,574)
Other expenses(311)(263)(1,010)(856)
Net investment income (loss)
26,615 22,727 77,084 62,721 
Total net realized and unrealized gains (losses) on investments and net investment income (loss)$235,141 $137,863 $664,542 $634,685 
Schedule of Realized Gain (Loss) on Investments
The components of net realized gains (losses) on investments are as follows:

Three Months EndedNine Months Ended
September 30,September 30,
($ in thousands)
2026202520262025
Fixed maturities and short-term investments$(6,983)$3,274 $(9,316)$4,140 
TS Hamilton Fund 173,705 106,081 563,788 420,002 
Net realized gains (losses) on investments$166,722 $109,355 $554,472 $424,142 
Schedule of Unrealized Gain (Loss) on Investments
The components of net unrealized gains (losses) on investments are as follows:

Three Months EndedNine Months Ended
September 30,September 30,
($ in thousands)
2026202520262025
Fixed maturities and short-term investments$(90,312)$7,227 $(137,483)$70,496 
TS Hamilton Fund 132,116 (1,446)170,469 77,326 
Net unrealized gains (losses) on investments$41,804 $5,781 $32,986 $147,822