Jim Simons' RenTech first bet on Tesla a decade ago - and the fund once held a stake in Elon Musk's automaker worth $12 billion today

• Jim Simons' quant fund, Renaissance Technologies, first bet on Elon Musk's Tesla as early as 2013.
• It bought a split-adjusted 2.7 million shares, worth $19 million then and over $500 million now.
• RenTech's stake peaked at 59 million shares in 2019, worth $12 billion at Tesla's stock price today.

Renaissance Technologies first invested in Tesla a decade ago, and its stake has whipsawed in value from under $400,000 to $1.6 billion since then, a Markets Insider analysis of Securities and Exchange Commission filings shows.

RenTech was founded by Jim Simons, a former NSA codebreaker and MIT math professor. It relies on algorithms to decide most of its trades, and ranks among the biggest and best-performing hedge funds in history.

The quantitative fund took an interest in Tesla as early as the second quarter of 2013, or about three years after Elon Musk's car company went public, filings show. It initially purchased 178,000 shares, or 2.7 million after adjusting for Tesla's 5-for-1 stock split in 2020 and its 3-for-1 stock split last August.

The electric-vehicle maker's stock price has surged by about 28 times since then, from a split-adjusted $7 to $198 as of Friday's close. RenTech's original position would be worth over $500 million today, compared with just $19 million when it was first purchased.

Over the next two quarters, Simons' fund bolstered its Tesla bet to a split-adjusted 9.1 million shares — worth $126 million at the time, and $1.8 billion as of Friday's close.

RenTech owned the automaker's stock on and off for the next few years. Its position ultimately peaked in the fourth quarter of 2019 at 59 million shares — worth $1.6 billion at the time and $11.7 billion today.

Simons' firm gradually pared its bet over the next couple of years, then slashed it from 2.2 million shares to only 1,400 shares in the third quarter of last year. The disposals cut the value of its position from $504 million to $371,000 in the space of three months.

Yet the quant fund piled back into Tesla last quarter, supercharging its wager to 3.4 million shares worth $419 million at the end of December, and $673 million as of Friday's close.

RenTech's Tesla ownership has been a rollercoaster ride, but it would be unwise to draw any major conclusions beyond the fact it has shown an enduring interest in the stock. Quant funds make sweeping changes to their portfolios on a daily basis, while quarterly filings only provide a snapshot of their holdings on a single trading day.

Moreover, portfolio updates exclude shares sold short, private investments, and overseas wagers, meaning they don't always a provide a full picture of a fund's investments.