| Schedule of Goodwill by Segment |
The following table presents the details of goodwill by segment as of June 30, 2025 and December 31, 2024: | | | | | | | | | | | | | | | | | | | | | | | | | | | | (in thousands) | | Market Making | | Execution Services | | Corporate | | Total | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Balance as of period-end | | $ | 755,292 | | | $ | 393,634 | | | $ | — | | | $ | 1,148,926 | |
|
| Schedule of Acquired Intangible Assets |
Acquired intangible assets consisted of the following as of June 30, 2025 and December 31, 2024: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of June 30, 2025 | | (in thousands) | | Gross Carrying Amount | | Accumulated Amortization | | Net Carrying Amount | | Useful Lives
(Years) | | Customer relationships | | $ | 479,130 | | | $ | (304,863) | | | $ | 174,267 | | | 10 | to | 12 | | Technology | | 136,000 | | | (136,000) | | | — | | | 1 | to | 6 | | Favorable occupancy leases | | 5,895 | | | (5,663) | | | 232 | | | 3 | to | 15 | | Exchange memberships | | 3,998 | | | — | | | 3,998 | | | Indefinite | | Trade name | | 3,600 | | | (3,600) | | | — | | | | 3 | | | ETF issuer relationships | | 950 | | | (950) | | | — | | | | 9 | | | ETF buyer relationships | | 950 | | | (950) | | | — | | | | 9 | | | | | | | | | | | | | | $ | 630,523 | | | $ | (452,026) | | | $ | 178,497 | | | | | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of December 31, 2024 | | (in thousands) | | Gross Carrying Amount | | Accumulated Amortization | | Net Carrying Amount | | Useful Lives
(Years) | | Customer relationships | | $ | 479,130 | | | $ | (281,315) | | | $ | 197,815 | | | 10 | to | 12 | | Technology | | 136,000 | | | (136,000) | | | — | | | 1 | to | 6 | | Favorable occupancy leases | | 5,895 | | | (5,645) | | | 250 | | | 3 | to | 15 | | Exchange memberships | | 3,998 | | | — | | | 3,998 | | | Indefinite | | Trade name | | 3,600 | | | (3,600) | | | — | | | | 3 | | | ETF issuer relationships | | 950 | | | (950) | | | — | | | | 9 | | | ETF buyer relationships | | 950 | | | (950) | | | — | | | | 9 | | | Other | | 1,125 | | | — | | | 1,125 | | | Indefinite | | | $ | 631,648 | | | $ | (428,460) | | | $ | 203,188 | | | | | | |
|
| Schedule of Finite-Lived Intangible Assets, Future Amortization Expense |
The Company expects to record amortization expense as follows over the next five subsequent years: | | | | | | | | | | (in thousands) | | | | Remainder of 2025 | | $ | 23,566 | | | 2026 | | 47,132 | | | 2027 | | 47,132 | | | 2028 | | 47,132 | | | 2029 | | 9,466 | | | 2030 | | 36 | |
|