Money is again pouring into bitcoin spot exchange-traded funds (ETFs), but an analysis says it is difficult to treat this as a clear signal that institutional investors are returning in earnest.

CoinShares said ETF inflows include not only expectations of price gains but also arbitrage demand, making it hard to interpret them by separating institutional and retail money, blockchain outlet Cointelegraph reported on Sept. 29.

James Butterfill (제임스 버터필), head of research at CoinShares, said inflows into U.S. cryptocurrency investment products in September totalled about $4.1 billion, with BlackRock's iShares Bitcoin Trust ETF, IBIT, accounting for more than 53 percent. In later tallies, September inflows into U.S. cryptocurrency investment products rose to about $4.44 billion and reached about $4.53 billion on a global basis.

Butterfill drew a line against judging institutional demand from the size of ETF inflows alone. Asked whether institutional investors are returning to the cryptocurrency market, he said, "It is possible, but it is difficult in the ETF market to separate institutional money from retail money."

The key is the nature of IBIT inflows. Butterfill said many institutional investors are using IBIT for a "bitcoin basis trade" strategy. That involves buying a bitcoin spot ETF while selling bitcoin futures to seek profits when the gap between spot and futures prices narrows. Butterfill said, "The basis trade yield is currently 6 percent, which is attractive to investors," and viewed that IBIT inflows should not be treated as a straightforward bullish bet because of this structure.

By asset, bitcoin investment products recorded the largest inflows at $2.84 billion. Ethereum followed at about $946 million, and zcash ranked third with $284 million. Over the most recent five trading days, about $3.5 billion flowed into cryptocurrency investment products across the industry.

CoinShares also pointed to a shift in investor interest beyond tokens themselves toward companies that generate profits from adopting cryptocurrencies. Butterfill said, "We need to pay attention to the movement of money within digital assets," adding that early-September tallies showed more than $100 million flowed into blockchain-related equities over the prior month.

Against this backdrop, the next key question is shifting to which companies generate actual revenue through tokenisation, payments and expanded trading infrastructure. Butterfill expected investors to examine such business models more closely over the next year. He cited an estimate that stablecoin assets could approach $4 trillion before the 2030s, and noted that Hyperliquid's daily trading volume is reaching as high as $9 billion.

September's ETF inflows show a recovery of interest in the cryptocurrency market, but their character is not simple. Money entering bitcoin spot ETFs mixes directional bets and arbitrage, highlighting that assessing institutional demand and market strength requires looking at structure as well as the size of flows.