** Shares of health insurer Molina Healthcare MOH.N fall 9.3% to $201.19 premarket

** Co says its Obamacare Marketplace business came under pressure during Q2 because a larger share of enrollees required costly medical care than it had anticipated

** MOH expects a $1.50 per share loss this year from the start of a new Florida Medicaid contract in Q4 and a $1 per share loss tied to the planned Medicare Advantage exit in 2027

** Brokerage Guggenheim says "the absence of more material Medicaid upside is likely to weigh on MOH's current premium valuation"

** Co reports Q2 adjusted profit of $1.51 per share, compared to analysts' estimate of $1.39 - LSEG data

** Co's Q2 revenue of $11.43 billion, beats analysts' estimate of $10.79 billion

** Up to last close, stock up 27.8% YTD