Stock in Rivian Automotive is dropping again, perhaps because Ford Motor and the electric-truck start-up said late Friday they aren’t going to develop electric vehicles together. Not everyone is convinced that is the reason, though: Even Tesla, and hope that it might split its stock, could be a factor.
While the S&P 500 and Dow Jones Industrial Average were both up about 0.7% near midday on Monday, Rivian (ticker: RIVN) stock was down about 15% to $108.50. That leaves it a bit less than $2 above the level of $106.75 where…