Another Signal gains after Elon Musk’s tweet

A two-word endorsement by Elon Musk has boosted Signal Messaging’s app downloads, as well as the stock of a tiny medical devices company that goes by a similar name.

“Use Signal,” the Tesla Inc. CEO wrote on Twitter on 7 January 2021, apparently referring to the encrypted messaging service. By the end of the day, Signal Advance Inc. shares had surged more than sixfold. That was enough to push Signal Advance’s rally more than 5,100% in three trading days giving it a market valuation of $390 million, according to Bloomberg.