Summary BlackRock's iShares Bitcoin Trust (IBIT) has entered the top 5 ETFs by net inflows in 2025, signaling strong investor demand. IBIT attracted $8.9 billion in inflows year-to-date, surpassing many established ETFs and highlighting growing mainstream acceptance of bitcoin exposure. There are concerns to consider, however, with signs of exhaustion in Bitcoin's weekly chart as well as a lack of demand for the other BTC ETFs in the US. I remain bullish BTC and by extension IBIT but think the top isn't terribly far away at this point. With Bitcoin ( BTC-USD ) hitting a fresh all-time high of $110,000 per coin, capital flows into the iShares Bitcoin Trust ETF (NASDAQ: IBIT ) are surging. Despite still personally having an affinity for fundamentals and usage, I've been making the case that Bitcoin's price has been entirely driven by capital flows for awhile. Demand from ETF buyers and from companies like Strategy ( MSTR )( STRF ) is what has been driving the coin's price. Thus, with a new all-time achieved on May 21st, we can look at metrics like net flow, supply, volume, and price moving averages to ascertain whether this is likely the start of a new leg that will take the coin much higher, or if it's more of a sign that we're close to the price top for this cycle. iShares Has Gone 'Full Pac-Man' Credit to Bloomberg ETF analyst Eric Balchunas for the 'full Pac-Man' characterization. What he's referring to is the IBIT ETF chewing up Bitcoin as though it were the vintage video game character eating dots in a maze. As of May 20th, IBIT had experienced $8.9 billion in net flow year to date: ETF Flows YTD (Eric Balchunas/X) That level of capital flow makes IBIT far and away the biggest beneficiary of investment demand relative to all of the other spot Bitcoin ETFs. Not only that, but IBIT has had the 5th largest year to date inflows of all ETFs . IBIT's hoard of BTC is now so large, that the 636k BTC held through IBIT is currently larger than the BTC supply held by the remaining US-based spot ETFs combined: Spot BTC Fund BTC Held USD Value Share of Supply iShares Bitcoin Trust 636,120 $69,798m 3.03% Fidelity Wise Origin Bitcoin Fund ( FBTC ) 199,840 $21,927m 0.95% Grayscale Bitcoin Trust ( GBTC ) 187,870 $20,614m 0.90% ARK 21Shares Bitcoin ETF ( ARKB ) 49,166 $5,395m 0.23% Grayscale Bitcoin Mini Trust ( BTC ) 42,718 $4,687m 0.20% Bitwise Bitcoin ETF ( BITB ) 38,268 $4,199m 0.18% VanEck Bitcoin Trust ( HODL ) 14,763 $1,620m 0.07% Invesco Galaxy Bitcoin ETF ( BTCO ) 8,780 $963m 0.04% CoinShares Valkyrie Bitcoin Fund ( BRRR ) 6,554 $719m 0.03% Franklin Bitcoin ETF ( EZBC ) 5,097 $559m 0.02% WisdomTree Bitcoin Fund ( BTCW ) 3,746 $411m 0.02% Sum ex-IBIT 556,802 $61,049m 2.65% Source: Bitcoin Treasuries, as of May 21st IBIT now controls more than 3% of BTC supply and holds more Bitcoin than Strategy. What I find so interesting about the surge in IBIT net flows this year is it is unique to this fund when factoring in the other spot ETFs in the US. Consider the year to date changes in supply held through each product: Fund BTC Balance 5/21/25 1/1/25 YTD Change iShares Bitcoin Trust 636,120 552,168 15.2% Fidelity Wise Origin Bitcoin Fund 199,840 202,800 -1.5% Grayscale Bitcoin Trust 187,870 206,835 -9.2% ARK 21Shares Bitcoin ETF 49,166 46,729 5.2% Grayscale Bitcoin Mini Trust 42,718 38,342 11.4% Bitwise Bitcoin ETF 38,268 40,196 -4.8% VanEck Bitcoin Trust 14,763 13,716 7.6% Invesco Galaxy Bitcoin ETF 8,780 8,780 0.0% CoinShares Valkyrie Bitcoin Fund 6,554 8,846 -25.9% Franklin Bitcoin ETF 5,097 7,567 -32.6% WisdomTree Bitcoin Fund 3,746 3,841 -2.5% Source: Bitcoin Treasuries, as of May 21st The 15% growth in BTC year to date for IBIT is top among all funds and IBIT is one of just four US spot ETFs that has positive BTC-denominated net flow year to date. One of the other funds with positive net flow in 2025 is Grayscale's Bitcoin Mini Trust. However, aggregating net flow totals for both of Grayscale's spot products has the issuer negative year to date as well. The VanEck fund's YTD net flow Is just 1,000 BTC year to date. ARK has done slightly better than that. But the point is, what IBIT is doing is impressive. Can This Continue? One thing that I think is worth paying attention to is the volume surge that took place in IBIT shares during the May 21st session. The fund did just under 99 million shares traded intraday. IBIT Daily Chart (TrendSpider) The chart above shows just three instances of at least 98 million shares traded intraday during green sessions so far this year; today is the third such instance. The prior two instances of green candle volume to this degree happened on days of significant directional pivots. The first such instance happened on January 23rd. IBIT subsequently fell by nearly 28% through the beginning of March. It happened again on April 7th. Much like what we saw in a volatile session for stocks that day, this spike signaled the low and IBIT has rallied more than 45% since. This spike is obviously coming after a large surge in price over a relatively short amount of time. The implication here being any directional price pivot in tandem with this volume surge would actually be to the downside. Taking a more long-term view of Bitcoin, the weekly chart might be exhibiting signs of impending exhaustion as well: BTC Monthly Chart (TrendSpider) I've marked moments where the 8 week MA flips over the 20 week MA with arrows. You can see this just happened for BTC this week (the week of May 19th). The last time it happened was the week of October 14th and the cross preceded a 56% surge over the next 2 months. However, at that time Bitcoin hadn't yet broken resistance and the coin was coming off seven months of sideways action. This time is a bit different. The coin is already working on a 7th consecutive green week and there is an obvious RSI-divergence concern to boot with RSI-14 quickly approaching overbought. Investor Takeaways While I don't think this BTC rally is over quite yet, I'm definitely getting a sense that we may be quickly careening to the peak for this cycle. Based on indicators that I follow, I wouldn't rule out a rally up to $120-125k BTC before we see a deep pullback in the coin. There are a variety of ways one can express that bullish BTC belief. My personal choice is FBTC. But there is no doubt that IBIT is the clear favorite among the spot ETFs in the US market. The fund has a competitive expense ratio, tremendous liquidity, and brand recognition. It also happens to be the outlier fund so far in 2025. Most of the spot ETFs have actually endured BTC-denominated outflow so far this year and IBIT currently controls more BTC supply than the rest of the funds combined. I'm of the view that this rally is getting close to its conclusion for this halving cycle. This coin goes as capital flows go and there is no question IBIT is acting like a BTC sponge - or as Pac-Man if you like that analogy better.
