Issuers of exchange-traded funds aren't having any luck when it comes to getting a bitcoin ETF to market. In lieu of ETFs tied to cryptocurrencies, some issuers are turning to blockchain funds. First Trust on Thursday launched the LEGR. The First Trust Indxx Innovative Transaction & Process ETF is the third blockchain ETF to come market. LEGR follows last week's debuts of the Amplify Transformational Data Sharing ETF BLOK and the Reality Shares Nasdaq Blockchain Economy ETF BLCN. BLCN and...