The following table details investments by major investment category, other than investments in related parties, at March 31, 2025 and December 31, 2024 (in thousands):

The Company's fixed-income securities portfolio was classified as held-to-maturity and reported at amortized cost as of December 31, 2024. The Company performed ongoing impairment evaluations, and did not record any current expected credit losses in previous periods as U.S. government and agency securities were assumed to have no risk of non-payment. The disclosed fair value of our fixed-income securities was calculated by a third-party pricing service. Valuation service providers typically obtain data about market transactions and other key valuation model inputs from multiple sources and, through the use of proprietary models, produce valuation information in the form of a single fair value for individual fixed-income and other securities for which a fair value has been requested. The inputs used by the valuation service providers included, but were not limited to, market prices from recently completed transactions and transactions of comparable securities, interest rate yield curves, credit spreads, liquidity spreads, currency rates and other information, as applicable. Credit and liquidity spreads are typically implied from completed transactions and transactions of comparable securities. Valuation service providers also use proprietary discounted cash flow models that are widely accepted in the financial services industry and similar to those used by other market participants to value the same financial information. The valuation models take into account, among other things, market observable information as of the measurement date, as described above, as well as the specific attributes of the security being valued, including its term, interest rate, credit rating, industry sector and, where applicable, collateral quality and other issue or issuer specific information. Executing valuation models effectively requires seasoned professional judgment and experience. The Company's fixed-income securities as of December 31, 2024 were classified as Level 2 in the fair value hierarchy. 

The Company has elected the practical expedient for fair value for its investment in limited partnership which is estimated based on our share of the net asset value (“NAV”) of the limited partnership, as provided by the independent fund administrator. The Company’s share of the NAV represents the Company’s proportionate interest in the members’ equity of the limited partnership.

Net investment income

Net investment income for the three months ended March 31, 2025 and 2024 is detailed below (in thousands):