Citi initiates Rivian with 'neutral,' $18 PT

** Citi initiates EV maker Rivian RIVN.O with "neutral" rating; sets $18 PT, implying a 13.5% upside to the stock's last close

** Brokerage believes monthly sales and production data over the next 6-9 months will likely be the most important metrics to monitor

** "Production of the R2 has increased from 150 units a week in June to 500 in August, and we expect the company to reach the 1,000 per week target by year-end" — Citi

** Average rating of 29 analysts is "hold;" their median PT is $18 — data compiled by LSEG

** Up to last close, stock had fallen 19.5% this year