MongoDB slumps as CEO exits after short tenure
** Database software firm MongoDB's MDB.O shares tumble 16.7% to $342 premarket
** Says CEO Chirantan "CJ" Desai has stepped down with immediate effect, names Dev Ittycheria as interim top boss
** Desai, who served as CEO for less than a year, to pursue a senior role at Meta META.O
** Reaffirms Q3 and FY27 forecasts
** 35 of 43 brokerages rate the stock "buy" or higher and eight "hold"; median PT is $470
** As of last close, stock down 2.2% YTD