Why Rivian Stock Popped 3.8% on Friday

Shares of electric vehicles manufacturer Rivian Automotive (RIVN 2.75%) got a 3.8% jump-start on Friday through 10:55 a.m. ET. You can thank investment banker Piper Sandler for that.Last night, after close of trading on a day when Rivian stock got clobbered for an 8% loss, Piper Sandler stepped in to save the day -- upgrading Rivian stock to an overweight rating and upping its price target on the EV stock to $21 per share. What the Wall Street analyst saidStreetInsider.com covered this story last night. As ...