** Shares of Rhythm Pharmaceuticals RYTM.O down nearly 2% in extended trading as co looks to raise equity

** RYTM shares on Weds finished up 36.6% at $89, a record high close, after its drug bivamelagon showed promise in mid-stage study for a rare type of obesity

** After the bell, Boston, Massachusetts-based co announced $150 mln stock offering

** Morgan Stanley, BofA, Stifel and Wells Fargo are jt bookrunners

** With ~63.6 mln shares outstanding, co has ~$5.7 bln current market cap, per LSEG data

** Shares up 59% YTD through Weds close

** All 13 analysts covering RYTM are bullish and median PT is $92

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

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