Grayscale Investments, an American cryptocurrency asset manager, is on track to launch the first spot Bitcoin (BTC-USD) ETF (exchange-traded fund) in the U.S. Grayscale is seeking to convert its existing $18 billion Grayscale Bitcoin Trust (OTCMKTS:GBTC) to a spot Bitcoin ETF as per a regulatory filing dated October 19. The Securities and Exchange Commission (SEC), which…