What happened

Shares of Rivian Automotive (RIVN 1.57%) rose 5.8% on Tuesday, furthering the electric-vehicle (EV) maker's rebound off its recent lows. 

So what

After sinking to a low of $50 in late January, Rivian's stock has rallied more than 30%. The sharp upward move has gained steam this week after securities filings showed that several major investors took stakes in the EV company. 

A person is looking at a tablet computer while sitting next to a laptop displaying a stock chart.

Image source: Getty Images.

The list was headlined by billionaire investor George Soros, whose family office bought 19.8 million shares of Rivian in the quarter ended Dec. 31. Notable investors also included the California Public Employees Retirement System (CalPERS), which manages nearly $500 billion in assets, as well as a host of other large pension funds. 

Now what 

Many investors like to peruse 13F filings to see what top fund managers are buying. The U.S. Securities and Exchange Commission (SEC) requires investment managers who oversee more than $100 million in assets to file these reports each quarter. When the current round of 13Fs that were released this week showed Rivian to be a new holding of multiple respected funds, many investors decided to also buy the EV maker's shares.

It should be noted, however, that these reports show institutional holdings as of the end of last year, so some funds might have sold Rivian's shares since then. Nevertheless, investors seem to be viewing the purchases by Soros, CalPERS, and others as a vote of confidence for the EV upstart's future, and they're bidding up Rivian's stock price in kind.