(Reuters) - Goldman Sachs ( GS ) and Morgan Stanley ( MS ) purchased a total of more than $600 million in spot bitcoin exchange-traded funds (ETFs) during the second quarter, regulatory filings showed on Wednesday.

The two banks joined a group of hedge funds and financial advisers that have waded into the products, which began trading in January 2024.

Goldman Sachs ( GS ) said in its quarterly disclosure to the Securities and Exchange Commission, known as a 13-F filing, that it had acquired about $418 million in several of the recently launched ETFs tied to the price of spot bitcoin.

Most of that sum reflected a stake of nearly 7 million shares in the iShares Bitcoin Trust, valued at about $238 million as of the end of the quarter, June 30. Goldman also took sizeable stakes in the Fidelity Wise Origin Bitcoin ETF and the Invesco Galaxy Bitcoin ETF ( BTCO ), and smaller positions in several other bitcoin ETFs launched in January.

Morgan Stanley ( MS ) also favored BlackRock's iShares bitcoin ETF, disclosing a 5.5 million share stake that was valued at $188 million as of June 30. The bank also disclosed smaller holdings in the Ark 21Shares Bitcoin ETF and Grayscale Bitcoin Trust ( GBTC ).

The 13F filings are one of the few ways to get a snapshot of how institutional investors are positioned at the end of every quarter. The positions may not reveal current holdings.

While the latest round of filings show the array of institutions in bitcoin ETFs may be growing, ETF issuers and analysts have said that so far, the products have mostly been dominated by individual investors.

Neither bank could be reached for comment on whether their positions were acquired on behalf of clients or for each firm's own account.

Some of the hedge funds that had established positions in the bitcoin ETFs earlier this year adjusted their holdings over the course of the second quarter, filings showed.

New York-based Hunting Hill Global Capital trimmed its exposure to both the Grayscale and Fidelity ETFs, but as of June 30 had a $18.32 million stake in the Bitwise Bitcoin ETF ( BITB ) and acquired a new $25.6 million position in BlackRock's ETF.

Adam Guren, founder and CEO of Hunting Hill, said his firm is an active trader of bitcoin products. "At any given time our trading activity can vary, and therefore our positions may shift," he said.

New York-based Millennium Management LLC disclosed that it cut its positions in three of the five bitcoin ETFs in which held stakes in the first quarter, while its exposure to the Ark 21Shares ETF was unchanged, and it increased holdings in the Bitwise product to nearly 2 million shares from about 1.2 million shares at the end of the first quarter.

Overall, the hedge fund had about $1.15 billion invested in the bitcoin ETFs at the end of the second quarter, down from the $2 billion it disclosed at the end of the first quarter. A spokesman for the firm declined to comment.

The price of bitcoin fell 12% during the quarter.