Grayscale CEO Michael Sonnenshein said Monday that converting Grayscale Bitcoin Trust (OTC:GBTC) to an exchange-traded fund remains a "top priority," according to a letter he wrote to shareholders. Sonnensheins' remarks come as the Security and Exchange Commission's final deadline on whether to approve Grayscale's conversion application nears. The agency's ruling on the 240-day application review process is scheduled for July 6. "Grayscale is unequivocally committed to converting GBTC to an ETF," Sonnenshein wrote, adding that the company "has been preparing for all possible post-ruling scenarios," as the SEC continues to prohibit other spot-based ETFs from coming to market. In March, for example, two spot bitcoin (BTC-USD) ETFs were rejected by the SEC. Meanwhile, Grayscale Bitcoin Trust's (OTC:GBTC) discount to net asset value keeps falling, standing at -29.3% as of June 24, according to data by YCharts. The sizable discount, which has widened since the beginning of March, comes as bitcoin (BTC-USD) craters around 65% from