BlackRock‘s Strategic Income Opportunities (SIO) fund has increased its position in the iShares Bitcoin Trust (IBIT) by 14% during the third quarter of 2025. The fund added 2,397,423 shares valued at roughly $155.8 million, marking a notable internal allocation as IBIT continues expanding amid growing ETF-driven market activity.
Institutional allocation to IBIT strengthens as ETF ecosystem scales
The increase reflects an internal capital shift rather than external inflows. IBIT now reportedly holds more than 600,000 BTC, with some disclosures placing total reserves as high as 662,841.3 BTC — about 3.658% of Bitcoin’s circulating supply. The product has delivered a trailing-year return of 107.50% and is estimated to generate approximately $191 million annually in fees.
Institutional adoption is expanding beyond BlackRock’s internal funds. The Abu Dhabi Investment Council tripled its IBIT allocation in Q3 2025, Two Sigma boosted its position by 14.9% in Q4, and firms including D.E. Shaw, Paul Tudor Jones and Goldman Sachs also increased exposure.
Although IBIT’s scale is growing, liquidity remains uneven at times. AInvest reported a one-day $473 million outflow and a $615 million valuation drawdown during a $1.17 billion collective ETF withdrawal window in August 2025, underscoring how concentrated flows can accelerate short-term volatility.
Market infrastructure is adapting to institutional volume. Nasdaq ISE has proposed raising IBIT option position limits from 250,000 to 1,000,000 contracts, and BlackRock is reportedly assessing an iShares Bitcoin Premium Income ETF as part of product diversification.
For treasuries and market participants, the benefits are tangible. Deeper ETF liquidity and enlarged derivatives capacity can improve execution and hedging efficiency, even if concentrated flows continue to drive intraday swings.
BlackRock’s 14% SIO allocation increase reinforces demand for regulated Bitcoin exposure. The move aligns with scaling ETF infrastructure, expanding institutional participation and rising strategic relevance of derivatives capacity.