Elon Musk sold an additional 22 million shares of Tesla (US:TSLA) stock worth about  $3.6 billion over three days from Dec. 12 to 14, according to a Form 4 filing with the US Securities and Exchange Commission. This follows Musk's November sale of around $4 billion worth of Tesla stock. Tesla's share price has hit 52-week lows in the past four consecutive sessions since December 16.

Musk wasn't the only one with some exciting insider action this week. Let's look at a few others that caught our eye. 

SoFi (SOFI)

While SoFi's trading near 52-week lows, unlike Elon Musk at Tesla, Chief Executive Officer Anthony Noto is a buyer, disclosing that he bought $5 million worth of SoFi (US:SOFI) stock or 1.13 million shares at an average of $4.42 each.

VF Corp (VFC)

VF Corp (US:VFC), the owner of brands such as Vans, The North Face, and Supreme, recently saw insider buying from directors. On Dec. 9, Mark Hoplamazian and Clarence Otis purchased 17,500 and 9,000 shares, respectively. Interim Chief Executive Officer and President Benno Dorer also demonstrated confidence in the company by buying 10,000 shares a few days later. Although Dorer has been with VF Corp for several years, he was only named CEO this month.

NRG Energy (NRG)

NRG Energy (US:NRG) Chief Executive Officer Mauricio Gutierrez bought 15,000 shares at $32.03 each on Dec. 15 for about $480,000, putting his stake at 1.1 million shares. Other insider buying at NRG Energy includes purchases by directors Heather Cox (1,500 shares at $31.32 on Dec. 16), Paul Hobby (3,500 shares at $31.37 on Dec. 16), and Elisabeth Donohoe (2,500 shares at $31.32). Directors Lawrence Coben and Antonio Carrillo also purchased shares on Dec. 15, with Coben buying 15,000 shares at $31.70 and Carrillo buying 9,000 shares at $31.71.

Rocket Companies (RKT)

Rocket Companies saw insider buying from CEO Jay Farner, who has been gobbling up stock through a 10b5-1 plan throughout December. Farner acquired another 237,900 shares, bringing his stake to 5.9 million, worth about  46.5 million on Friday. Director Matthew Rizik, the Treasurer, Chief Financial Officer, and Chief Tax Officer for Rock Holdings, also bought 20,700 shares this month through a 10b5-1 plan.

Karat (KRT)

Alan Yu, Chairman and Chief Executive Officer of Karat Packaging (US:KRT), has continued to buy Karat stock despite its shares hovering near a 52-week low. Yu bought stock on seven separate days this month, accumulating 43,100 shares for over $600,000 and building his stake to more than 7.4 million shares.