BlackRock Bitcoin ETF Powers Into Top 5 ETFs With Largest YTD Inflows

BlackRock Bitcoin ETF (IBIT) exploded into the top five U.S. ETFs by year-to-date (YTD) inflows as of May 21, 2025. On that day, Bloomberg-tracked data quoted by MilkRoad showed IBIT had attracted roughly $9.0 billion in net inflows for 2025, vaulting it past major fund categories.

This was a dramatic leap: IBIT had ranked only #47 among U.S. ETFs a month earlier. For context, as of May 7, IBIT’s YTD inflows were about $6.96 billion – already the 6th-largest of all ETFs.

That pace outstripped the SPDR Gold Trust (GLD), which had $6.5 billion and was #7 on May 7. By mid-May, IBIT’s position had climbed further: Bloomberg data put GLD only at #14 on the YTD flows list, with IBIT at #5.

BlackRock Bitcoin ETF Massive Inflows in Mid-May

The inflows were driven by an unprecedented inflow of new capital in late May. U.S.-listed spot Bitcoin ETFs drew about $934.8 million on May 22 alone.

As reported by The Coin Republic, BlackRock Bitcoin ETF IBIT accounted for $877.2 million of that one-day total, roughly 94% of all BTC ETF inflows that day. In effect, IBIT was the single biggest net inflow ETF in the U.S.

Over the three trading days from May 21–23, IBIT added roughly $1.4 billion more in inflows. This single-week pull was part of a larger monthly trend: Bloomberg data indicate BlackRock Bitcoin ETF took in on the order of $7–8 billion in about one month.

By comparison, most traditional funds saw modest flows. SPDR Gold Shares (GLD) – the largest gold ETF – had slipped to just #14 by YTD inflows.

Other big equity or bond ETFs did not come close to IBIT’s surge. In fact, on May 22, BlackRock Bitcoin ETF outpaced Vanguard’s giant S&P 500 ETF (VOO).

Balchunas reported that IBIT took in $877.18 million vs. about $558 million for VOO. Put simply, traditional “safe” or broad-market ETFs were being eclipsed in daily flows by the Bitcoin fund.

Growing Institutional Appetite in Crypto Assets

Analysts attribute the latest inflows into the BlackRock Bitcoin ETF to a strong institutional appetite amid Bitcoin’s rally. Bitcoin hit new highs (approximately $112,000) in late May, which coincided with the surge in ETF demand.

“All the BTC ETFs are elevated, most gonna see 2x their [daily] average [flows] incoming,” Bloomberg ETF analyst Eric Balchunas wrote on May 22.

His observation highlights that every U.S. Bitcoin ETF was drawing above-average interest during this period. Balchunas also noted IBIT’s outsized volume, calling May 21 and May 22 its highest-volume days to date. In sum, the data and expert commentary point to a classic Bitcoin ETF “feeding frenzy” as crypto prices broke records.

This story is grounded in Bloomberg’s own ETF flow data and industry analysis. By May 21, Bloomberg’s rankings and terminal feed showed IBIT leapfrogging large money-market and gold funds. Balchunas’ figures confirm IBIT’s YTD inflows of about $7–8 billion in early May.

All the key numbers (May 21 flows, IBIT’s $1.4B weekly gain, $7B monthly total, GLD’s #14 rank) come from Bloomberg-affiliated trackers or analysts. BlackRock Bitcoin ETF has become a top draw for investors in 2025, reflecting a growth of institutional capital in crypto.