System1, Inc. (SST) Institutional Ownership

Ownership Summary

System1, Inc. (NYSE:SST) showed up in the 13F filings of 23 institutional investors as of December 2025.

• They owned 10.1% of outstanding stock in December 2025, down from 41.6% the prior quarter.
• Their total shares held in SST decreased -75.36% from the prior quarter, while the number of investors in System1 decreased 61.67% year over year.
• Among the 23 funds, 5 bought more System1 shares, 13 sold down, and 5 held their ground.
• In total, institutional investors held 815.64K shares in System1 as of December 2025, down by 2.5Mn shares quarter on quarter, and down 34.7Mn shares year over year.
• As of December 31, 2025, Cannae Holdings, Inc. held the largest stake in System1 with 356.8K shares, accounting for 4.43% of total shares outstanding.
• The most significant purchases of SST for the quarter ending December 2025 came from XTX Topco Ltd (12.38K), CITADEL ADVISORS LLC (2.7K), RENAISSANCE TECHNOLOGIES LLC (1.5K), Tower Research Capital LLC (TRC) (348), BlackRock, Inc. (37).
• Top sellers of SST stock for the quarter ending December 2025 included Cannae Holdings, Inc. (2.34Mn), Bank Of America Corp /De/ (161.59K), MILLENNIUM MANAGEMENT LLC (3.11K), Royal Bank Of Canada (1.29K), FMR LLC (815).
• Per Business Quant data, the top 10 holders of System1 for the quarter ending December 2025 are Cannae Holdings, Inc. (356.8K), Bank Of America Corp /De/ (161.55K), Cerity Partners LLC (116.84K), VANGUARD GROUP INC (46.93K), MILLENNIUM MANAGEMENT LLC (35.45K), BlackRock, Inc. (24.25K), RENAISSANCE TECHNOLOGIES LLC (18.62K), GEODE CAPITAL MANAGEMENT, LLC (14.36K), CITADEL ADVISORS LLC (12.76K), XTX Topco Ltd (12.38K).