** Shares of cybersecurity company Tenable Holdings Inc TENB.O fall 1.15% to $30.04
** Co appoints Matthew Brown as chief financial officer, effective immediately
** Brown joins from Altair Engineering, where he served as the CFO
** Brown succeeds Steve Vintz, who was recently appointed as co-CEO alongside Mark Thurmond
** Including session's moves, the stock has fallen ~24%, YTD