** Oilfield services firm Atlas Energy Solutions' shares fall ~1.5% to $20.8

** Citigroup downgrades AESI to "neutral" from "buy"; cuts PT to $22 from $23

** Brokerage says AESI's stock rallied despite its sand production segment's fundamentals weakening

** "Rally pushed stock to a full valuation" - Citigroup

** Nine of 11 brokerages rate the stock "buy" or higher, 2 "hold"; their median PT is $23 - LSEG data

** Including session's moves, stock up ~22.7% YTD

(Reporting by Prakhar Srivastava in Bengaluru)

((Prakhar.srivastava2@thomsonreuters.com))