Elon Musk has been called just about every flattering name in the book, from "visionary investor" to "genius" to "the modern-day Tony Stark." One hopeful author even called him "our best hope yet for moving beyond fossil fuels." He's a Silicon Valley superstar and has one of the greatest rags-to-riches stories you can read.

On March 23, 2018, Elon Musk deleted facebook pages for Tesla and SpaceX in response to the #DeleteFacebook trend in the aftermath of Facebook's Cambridge Analytica scandal. 

An abbreviated list of Musk's best investments includes PayPal Holdings, Inc. (NASDAQ: PYPL), SpaceX, DeepMind (NASDAQ: GOOGL), Tesla Inc. (TSLA), and The Boring Company.

PayPal

A short list of PayPal's investors and executives reads like a who's who list of the modern tech industry. The popular online payment system was co-founded by, among others, Ken Howery, Max Levchin, Peter Thiel and Musk. 

Musk no longer holds a stake in PYPL, having exited his position after eBay purchased the company for $1.5 billion worth of stock in 2002 — something Carl Icahn helped undo more than a decade later. Musk reportedly earned between $165 million and $175 million for his part — not a bad return on the $10 million Musk used to co-found X.com, the precursor to PayPal.

SpaceX

As he's done with the proceeds from prior corporate acquisitions, Musk used most of his PayPal fortune to found Space Exploration Technologies Corporation, more commonly known as SpaceX. By most accounts, Musk sank $100+ million to get SpaceX off the ground in 2002.

The company has been a remarkable success, both financially and technologically. NASA awarded SpaceX with a lucrative contract in 2006. It launched Falcon 1, the first-ever private liquid-propellant rocket to reach orbit, in 2008. Two years later the Dragon spacecraft actually reached the International Space Station (ISS). In 2011, NASA granted SpaceX a second contract to help shuttle crew between the ISS and Earth.

As a private company, SpaceX is more difficult to value than PayPal. However, an August 2017 round of private financing put the company's worth around $21.5 billion. Musk still owns a controlling interest, which means his share is worth far more than the $100 million he originally invested. Expect Musk to earn a huge sum if SpaceX is ever taken public.

SpaceX has made space travel exciting again, and Musk is very open on social media with the company's efforts to push space science forward, like landing a rocket upright onto a landing pad in the middle of the Atlantic Ocean.

Musk sent his most powerful rocket yet, the Falcon Heavy, on its first test flight on February 6th, 2018. Musk previously announced that if everything went according to plan with the 230-foot-tall rocket, he would send the rocket into space carrying a top of the line Tesla Roadster on a trek towards Mars. Musk has also made clear his intentions to take not just cars, but humans to Mars by 2024. 

DeepMind Technologies

Musk struck buyout gold again with his artificial intelligence company DeepMind Technologies. The company launched in late 2010 with Musk as one of the key angel investors. The company would eventually sell to Google for an unconfirmed amount, but most reports put the value between $400 and $600 million.

Musk is famously worried about artificial intelligence overtaking humans and invested in DeepMind not to make money, but, as he said to Vanity Fair, "to give me visibility into the rate at which it was developing." Musk has said what he learned from gaining that visibility was enough to change his way of thinking about all his ventures, including furthering his plans to colonize Mars in case humans need to escape Earth due to a robot uprising. Yes, this is a real thing Elon Musk is worried about. 

Tesla Motors

Musk was not a founding member of the Tesla team, but he did lead an early round of financing in 2004. After a very disappointing run up through 2008, Musk went from board member to CEO, even though he still served as CEO of SpaceX. Since that time, Tesla went public and saw its stock appreciate from just $19 per share in June 2010 to $344.78 per share as of June 13, 2018. 

In November of 2017, Tesla announced the creation of fully electric semi-trucks, which are set to hit the road in 2019. These semis have already seen huge preorders from companies such as UPS, PepsiCo, and more. Tesla also produces the sporty Model S, the Model X SUV, the recently released Model 3 sedan, and the high end Roadster supercar. 

Speaking at South by Southwest 2018, a music and technology festival, Musk said that Tesla is the only public security he owns.

According to a June 2018 SEC filing, Musk spent about $25 million on Tesla share on June 12 and 13. He purchased 72,500 shares, at weighted average prices between $342.78 and $347.01.

The Boring Company

Musk founded the tunnel construction "Boring Company" in late 2016. The basic idea behind The Boring Company is that traffic is awful, and why travel above ground when there's miles and miles of unused earth beneath us. The goal with The Boring Company is to reduce the cost of tunneling while also speeding up production. Boring Company hopes to achieve this by making smaller tunnels and juicing up the power of Boring Machines. 

Musk has hopes that The Boring Company, which has projects in various states in Los Angeles, Hawthorne, the East Coast, and Chicago, will be the key to unlocking hyperloop travel, one of Musk's passions. To fund the project, Musk did what any entrepreneur would do, he started selling hats. On December 16, 2017, Musk announced he had sold 42,000 Boring Company hats and raised $840,000. After hitting his goal of 50,000 hats sold, Musk began selling the next branded Boring Company product; a flamethrower. For just $500, Musk offered fans the ability to unleash their inner supervillian with the Boring Company Flamethrower, which netted the company over $7.5 million in just a few days.  

The Boring Company is currently burrowing its way beneath LA to create a 6.5 mile proof of concept tunnel. If the tunnel gets government approval, Musk can go full steam ahead and tunnel his way to a brighter future. 

In May 2018, Musk announced on Twitter that The Boring Company had established a partnership with the Los Angeles Metro to work on an experimental tunnel under the city. Musk later tweeted that the Boring Company's first tunnel under LA was almost complete, and also published a time-lapse video of a round-trip through the tunnel on Instagram. While it is still pending regulatory approval, it was reported that Musk planned to offer free rides to the public in a few months.

In June 2018, Chicago Mayor Rahm Emanuel announced that The Boring Company will build and operate a multi-billion dollar rapid transit link between O’Hare International Airport and Downtown Chicago. The Boring Company plans for the trip to take approximately 12 minutes each way, compared to the 40 minute trip via the city’s Blue Line, by using electric vehicles that run through new underground tunnels. The company will fund the entire project with no taxpayer subsidy.