** Used autos retailer CarMax's shares KMX rise 2.6% to $76.20 ** Stephens upgrades rating to "overweight" from "equalweight" ** Raises price target to $90 from $86, representing 7.7% upside to stock's last close ** Brokerage has positive view for 2025 operations estimates, especially H1, based on consistency in co's credit metrics as well as used unit gross profit and sales ** "We believe KMX will likely marginally benefit from most tariff scenarios, at least in year 1," brokerage says ** 11 of 18 brokerages rate stock "buy" or higher, 5 "hold" and 2 "sell"; their median PT is $95 - LSEG-compiled data ** KMX will release Q4 results before the bell on April 10 ** Including session's gains, stock had fallen 6.8% YTD