Rivian (RIVN) COO Resigns Amid Production Challenges, Stock Falls (revised) Posted byZacks Equity Research January 11, 2022 Leave a comment on Rivian (RIVN) COO Resigns Amid Production Challenges, Stock Falls (revised) Rivian’s (RIVN) COO steps down at a time when the company is stretched with production ramp-up challenges. This brings down its shares below its IPO price.