MicroStrategy (NASDAQ:MSTR) stock edged down 1% in Friday after-hours trading after it agreed to sell up to $500M in common shares in a new offering, according to an SEC filing.Under the terms of the sale agreement, MicroStrategy (MSTR) may sell shares in amounts and at times to be determined by the company from time to time.MSTR did not disclose what the new capital would be used for, though the move comes after it's bitcoin (BTC-USD) impairment loss soared to $1.09B in Q2 from $618.9M a year before.At the start of September, MicroStrategy shares fall in wake of DC AG's suit against company's chairman.