KEY POINTS
  • A thinly traded device maker called Signal Advance soared for the third consecutive trading session after Elon Musk said to "use Signal," even though he was referring to a messaging app that has nothing to do with the company.
  • Musk said Sunday he plans to donate more to the app, which is funded by a nonprofit organization.
BERLIN, GERMANY - SEPTEMBER 02: Tesla head Elon Musk arrives at a retreat of the German Christian Democrats CDU/CSU Bundestag faction on September 02, 2020 in Berlin, Germany. Musk is currently in Germany where he met with vaccine maker CureVac, with which Tesla has a cooperation to build devices for producing RNA vaccines, yesterday. Today he is rumoured to also the site of the new Gigafactory under construction near Berlin.
Maja Hitij | Getty Images News | Getty Images

Four days after Tesla CEO Elon Musk prompted Twitter followers to "use Signal," a reference to the Signal encrypted messaging app funded by a nonprofit organization, investors pushed even higher the price of Signal Advance, a small component manufacturer whose stock trades over the counter.

During Monday's trading session, the stock rose 438% and reached a high of $70.85, up from a closing price of 60 cents on Jan. 6, a day before Musk's tweet. The stock saw its highest trading volume since going public in 2014 on Monday; more than 2 million shares changed hands, while on Jan. 4, not a single share of the stock was traded. Signal Advance, which reported receiving no revenue in 2015 and 2016, is now worth more than $3 billion.