The primary academic analysis of SEC 13F filings covering Q1 2024 through Q4 2025 provides structured evidence showing net reductions in institutional Bitcoin ETF holdings during Q4 2025, quantified at roughly 25,000 BTC equivalent. CF Benchmarks independently analyzed quarter-over-quarter flows from aggregated 13F data for ten spot Bitcoin ETFs and confirmed substantial net sales in the same magnitude range. Both datasets reference primary filings on the SEC EDGAR system, lending high credibility to the figures. Secondary summaries from institutional and industry sources reinforce a consistent narrative of net outflows from institutional holders in Q4 2025. While some social posts and blogs mention counterexamples such as specific funds (e.g., Mubadala) increasing exposure, those are isolated cases that do not offset the aggregate institutional selling trend identified in the filings. Given the strong agreement between two highly authoritative datasets based directly on primary evidence and the consistency across secondary sources, the claim that approximately 25,098 BTC were sold by institutional investors from spot Bitcoin ETFs during Q4 2025 is highly probable, with limited contradictory evidence.