The rare investments that recently went into Grayscale ’s Bitcoin ( BTC ) exchange-traded fund (ETF) dried up within two days amid massive outflows.

The Grayscale Bitcoin Trust (GBTC) recorded inflows worth $66.9 million in May after bleeding over $17.5 billion in 78 days straight since its Jan. 11 launch. The investments came in on May 3 and 6, each day attracting $63 million and $3.9 million, respectively.

However, the inflow trajectory failed to maintain momentum in the coming days.

Investment inflows and outflows for U.S. spot Bitcoin ETF market, in million dollars. Source: Farside

GBTC recorded outflows worth $28.6 million and $43.4 million on May 7 and 9, respectively — essentially undoing the investments it had recently brought in. On both days, Grayscale was the only Bitcoin ETF issuer to report outflows.

The rest of the nine Bitcoin ETFs approved by the U.S. Securities and Exchange Commission (SEC) recorded positive or no investments during the timeframe.

On average, the Grayscale Bitcoin Trust lost $211 million every day since launch. However, contributions from other participants keep the net balance at a positive $11.7 billion.

It is important to note that all Bitcoin ETF issuers, except GBTC, stand on positive inflow balances. Out of the lot, BlackRock’s iShares Bitcoin Trust (IBIT) attracted the highest investments, racking up nearly $15.5 billion to date.

Other prominent issuers include Fidelity Wise Origin Bitcoin Fund (FBTC), Bitwise Bitcoin ETF (BITB) and Cathie Wood’s ARK 21Shares Bitcoin ETF (ARKB), which currently sport net inflows of $8.1 billion, $1.7 billion and $2.2, respectively.

Related: Grayscale Bitcoin ETF takes the slow train to recoup $17.4B outflows

Speaking exclusively to Cointelegraph at Paris Blockchain Week in April, VanEck CEO Jan VanEck said the retail sector brings in 90% of Bitcoin ETF inflows . “You’ve had some Bitcoin whales and some other institutions move some assets in, but they were already exposed to Bitcoin,” he said.

Jan VanEck (right) on stage at Paris Blockchain Week with Cointelegraph journalist Gareth Jenkinson. Source: Cointelegraph

However, VanEck anticipated the arrival of some major institutional investments from banks and traditional firms by May.

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