In today’s “Expert Spotlight,” we will look at two top picks, Riot Blockchain (NASDAQ:RIOT) and Argo Blockchain (NASDAQ:ARBK) (GB:ARB), that senior Roth Capital analyst Darren Aftahi is optimistic about. Aftahi is the Managing Director of Roth Capital and an expert in the Internet, Media & Enabling Technologies sectors. Aftahi has deep experience covering U.S. and Canadian technology stocks. According to the expert analyst, the major factors which could impact the performance of these blockchain miners include stiff competition, high power costs, the capital-intensive nature of mining, government regulations, and the price of Bitcoin (BTC-USD).