Bitcoin ETFs Outperform S&P 500 as Institutional Capital Reallocates

BlackRock’s iShares Bitcoin Trust (IBIT) has led a surge in inflows for Bitcoin exchange-traded funds (ETFs), recording $129 million in net inflows on September 24, 2025, according to data from SoSoValue. This marked a significant rebound for the fund after two consecutive days of outflows, as institutional demand for Bitcoin rebounded amid shifting macroeconomic conditions. The inflow brought IBIT’s cumulative net inflows to $60.78 billion, with total assets under management (AUM) reaching $87.2 billion, solidifying its position as the largest Bitcoin ETF by volume and market share.

The inflow streak for BlackRock’s ETF extended to 19 consecutive days as of May 2025, the longest of the year, with $1.03 billion in inflows recorded over a single trading week. This trend coincided with Bitcoin’s price rebound above $90,000 in April and $100,000 in May, driven by renewed institutional adoption and anticipation of U.S. regulatory clarity. The fund’s dominance was further underscored in early September, when it led a $887 million net inflow from September 15 to 19, contributing to Bitcoin ETFs’ total AUM of $149.7 billion, or 6.62% of Bitcoin’s market cap.

BlackRock’s ETF outperformed traditional benchmarks during the period, surpassing the inflow volume of its own S&P 500 ETF. Bloomberg ETF analyst Eric Balchunas attributed this to a “structural shift” in institutional capital allocation, with Bitcoin increasingly viewed as a strategic asset class. The iShares Bitcoin Trust’s inflows were driven by a combination of macroeconomic factors, including expectations of Federal Reserve rate cuts, and a growing appetite for digital assets among institutional investors.

The ETF’s performance highlights broader market dynamics, including a divergence between Bitcoin and Ethereum products. While Bitcoin ETFs attracted $887 million in September, Ethereum ETFs recorded sustained outflows, totaling $79.4 million on September 24 alone. This contrast underscores Bitcoin’s role as a primary on-ramp for institutional capital in the crypto market, with BlackRock’s product capturing a disproportionate share of inflows.

Analysts caution that the inflow trends remain sensitive to macroeconomic volatility and regulatory developments. The Federal Reserve’s recent rate cut and upcoming inflation data releases have introduced uncertainty, while concerns about Bitcoin’s scalability and environmental impact persist. Despite these risks, the ETF’s growth reflects a maturing market where Bitcoin is increasingly integrated into traditional financial portfolios.

[1] Bitcoin ETFs Record $241M Inflows – ETH ETFs Continue Outflows (https://finance.yahoo.com/news/bitcoin-etfs-surge-back-record-191735899.html)

[2] BlackRock’s Bitcoin ETF Inflow Streak Reaches 19 Days (https://cointelegraph.com/news/blackrock-ibit-bitcoin-etf-inflow-streak-largest-2025)

[3] Spot Bitcoin ETFs Achieve $887M Net Inflow in September (https://coinlive.me/spot-bitcoin-etfs-887m-september-2025/)

[4] BlackRock’s Bitcoin ETF Surpasses S&P 500 ETF Inflows (https://theccpress.com/ishares-bitcoin-etf-leads-inflows-2025/)

[5] Bitcoin, Ethereum ETFs See Strong Inflows Led by BlackRock (https://themarketperiodical.com/2025/09/20/bitcoin-ethereum-etfs-see-strong-inflows-led-by-blackrock-2/)