Passive investing through exchange-traded funds may be losing its appeal. Tidal Financial Group Chief Revenue Officer Gavin Filmore finds many of his clients are no longer satisfied with buying popular ETFs tied to market indexes. "I think investors are looking beyond just the let's call it the 'VOO and chill approach' where you just buy the index in an ETF, which is a great approach but they're looking for diversification ," Filmore told CNBC's "ETF Edge" this week." "And they're not finding