While awaiting a Spot Bitcoin ETF approval, Grayscale announced the FTSE Grayscale Crypto Sector Index Series, a novel way to look at the digital asset market and measure the performance of the rapidly growing crypto space. What Happened: Digital currency asset manager, Grayscale Investments launched five crypto sector indices along with London-based index provider FTSE Russell, a subsidiary of the London Stock Exchange, the company announced on Tuesday. The joint product launch will be called the “Crypto Sector Index Series” including several indices that track the prices of various digital a…