Tesla's First Acquisition Riviera Tool Is Trading Up 10,000%

a Grand rapids, Michigan-based auto parts maker, the Detroit Free Press reported on Wednesday night. Traders seems to have discovered this little-known company late Thursday morning.

, a penny stock, was up more than 10,000 percent (or roughly $0.49) at $0.51 around 1:00 p.m. ET. The little-traded over-the-counter stock saw a flurry of buying action around 11:10 a.m. ET. The activity died died down about an hour later before picking back up again. The stock's 30-day average trading volume was a little more than 10,000 shares. Its traded nearly 6 million shares so far in Thursday's session. Riviera Tool was incorporated in 1967. The Free Press said the company "makes stamping parts that are shipped to Tesla's assembly plant in Fremont, Calif., [and] has about 100 employees. Tesla is expected to retain those workers and eventually rename the operation Tesla Tool & Die, said the source who is not authorized to speak publicly about the transaction." This is Tesla's first acquisition since being founded in 2003. Shares of Tesla were down about 0.35 percent (or $0.81) at $229.62 after reporting earnings on Wednesday night.