** First Advantage's FA.O shares jump 6% to $16.49 before the bell as employment background screening co poised to join S&P SmallCap 600 index .SPCY next week

** FA to replace Kennedy-Wilson Holdings KW.N in SPCY effective Tues, June 16, S&P Dow Jones Indices announced late Thurs

** Real estate investment firm KW being acquired by consortium led by its CEO William McMorrow and Canadian insurer Fairfax Financial FFH.TO

** Stephens analyst Melissa Roberts said in a note she expects passive funds will need to purchase 10.8 mln FA shares, or about 10 days of buying demand, based on stock's 3-month avg daily trading volume

** Atlanta, Georgia-based FA has ~171.5 mln shares outstanding for roughly $2.7 bln market cap

** Through Thurs, stock up 41% over the past three months, putting it up 7% YTD

** 5 of 10 analysts rate the stock "strong buy" or "buy", 5 "hold"; median PT $18, LSEG data reflects