According to Blockworks, 13F filings, which are a measure of institutional interest in Bitcoin ETFs, have been steadily coming in since the start of last month and are expected to continue until mid-May. These forms are mandatory filings with the Securities and Exchange Commission that disclose the quarterly holdings of institutions managing $100 million or more.

BNP Paribas and BNY Mellon are among the largest institutions to disclose holdings in a Bitcoin ETF. BNY Mellon's 13F reveals that it owns nearly 20,000 shares of IBIT and approximately 7,000 shares of Grayscale's Bitcoin ETF GBTC. BNP Paribas, however, owns only about 1,000 shares of IBIT.

Smaller firms with larger holdings have also been identified. For instance, Pittsburgh-based registered investment manager Quattro Advisors owns 468,200 shares of BlackRock's ETF, according to their 13F. Legacy Wealth Management disclosed ownership of over 350,000 shares of Fidelity's ETF.

One of the largest IBIT holders is Yong Rong, which disclosed in its 13F that it holds over a million shares of BlackRock's fund, making BlackRock one of the largest holdings in the manager's portfolio. Bloomberg's Eric Balchunas noted that Yong Rong is not the only Hong Kong asset manager investing in Bitcoin ETFs. Ovata also holds multiple Bitcoin ETFs, including those from Fidelity, Grayscale, and Bitwise, alongside IBIT.

These companies join a list of firms that have previously disclosed their holdings, including Brookstone Capital Management, which owns both Fidelity and Bitwise's ETFs, and LexAurum, another IBIT holder.

As previously reported by Blockworks, some analysts believe that this is just the beginning and not to expect too much from this first quarter of 13Fs. However, as the filings continue to be monitored, the interest may increase. Some of the larger institutions tend to file closer to the deadline.