** Shares of Corebridge Financial CRBG.N up 3.8% premarket to $32.73 as life insurance and retirement services firm poised to join S&P MidCap 400 index .IDX this week

** CRBG to replace utility owner Allete ALE.N in the IDX effective on Weds, Dec 17, S&P Dow Jones Indices announced late Fri

** ALE being acquired by BlackRock's BLK.N unit Global Infrastructure Partners and C anada Pension Plan Investment Board in $6.2 bln deal

** Stephens analyst Melissa Roberts said she expects passive funds will need to purchase 33 mln CRBG shares which implies 6.5 days of buying demand

** CRBG has ~520.5 mln shares outstanding for $16.4 bln market cap through Fri

** American International Group AIG.N last month carved its stake in CRBG to ~50 mln shares in secondary offering, days after CRBG posted Q3 net income of $144 mln, reversing a loss from prior year

** 10 of 15 analysts rate CRBG stock "strong buy" or "buy", 5 rate "hold" and median PT is $39, per LSEG data

** Through Fri close, stock up ~5% in 2025

(Lance Tupper is a Reuters market analyst. The views expressed are his own)

((lance.tupper@tr.com 1-646-279-6380))