The FMP ETF Holder endpoint provides a list of all the institutional investors that own shares of an ETF. This information can be used by investors to track the ownership of an ETF and to identify potential trends. For example, an investor may want to know which institutions are buying or selling shares of a particular ETF.
Investors can also use ETF holder data to identify ETFs that are popular among institutional investors. This may be a signal that these ETFs are well-managed and have a good track record.