After a difficult week and an even worse month, Rivian (NASDAQ:RIVN) stock is riding high again on two positive updates.Last week brought the unveiling of the firm’s lower-cost R2 electric vehicle (EV) platform, which promises to help boost shares in the long term. However, that’s not why shares are up today. First off, recent data shows that Rivian enjoyed a positive start to the year in terms of registrations, despite RIVN stock struggling. Plus, the electric truck producer will now be able to offer drive ...