Bionano Genomics Inc. /zigman2/quotes/208673493/composite BNGO -9.81% on Tuesday announced its second share sale in less than a month amid an unexplained spike in its price and volume, sending shares down in after-hours trading. Bionano did not disclose a targeted number of shares nor price in its offering, but the stock still fell more than 8% in the extended session. Bionano previously sold 29 million shares at $3.05 a share less than two weeks ago, as shares traded on the open market for more than $5. The stock has since continued to ride higher, closing at an all-time high of $9.14 Tuesday. Bionano shares traded for less than $1 for much of 2020, before prices shot higher just before the end of the year despite no public announcements about changes at the genome-analysis company, which lost nearly $30 million on sales of $4.5 million in the first nine months of 2020.