18 celebrities who are huge tech investors

It's only appropriate that Iron Man himself take an interest in tech. In 2011, Robert Downey, Jr. founded Downey Ventures to make angel investments in startups and incubate consumer entertainment tech companies.

He was in on an early $36 million investment in Maker Studios, a network that creates YouTube content such as Epic Rap Battles in History. Maker also works with young stars such as PewDiePie and develops videos for Disney, which acquired Maker in 2014 for $500 million.

(Note the synergy at work; Disney owns Marvel Studios, which produces Downey's Iron Man and Avengers films.)

The Oscar-winning Revenant actor invested $4 million in photo- and video-sharing network Mobli in 2011, a move that attracted other celebrities such as Lance Armstrong, Serena Williams and Tobey Maguire.

DiCaprio also came on as a branding and marketing adviser for the app, one of Instagram's competitors. Mobli has about 1 million active users and an estimated $89 million in equity funding.

DiCaprio has also put money in health-monitoring app Cue, the smart-home product developer Zuli, recycling solutions company Rubicon Global and Casper.

Fantastic Four actress and mom Jessica Alba launched e-commerce site The Honest Co. alongside ShoeDazzle co-founder Brian Lee, in 2011, with 17 eco-friendly baby and household products.

Since then, her site has increased to selling 120 products (including a $170 vegan leather diaper bag), launched the beauty brand Honest Beauty, debuted a corresponding shopping app. Lawsuits notwithstanding, the company is worth an estimated $1 billion.

Hip-hop king Jay-Z acquired music-streaming service Aspiro for $56 million, and then relaunched it as Tidal in 2015.

He attracted a slew of big-name musical co-owners, including his wife, Beyoncé, Rihanna, Kanye West, Nicki Minaj, Daft Punk, Jack White, Madonna, Arcade Fire, Alicia Keys, Usher, Chris Martin, Calvin Harris, deadmau5, Jason Aldean, J. Cole and T.I.

Despite criticism for the paid subscription service, it has received some praise for its lossless audio and hi-def music videos. It has attracted more than 3 million subscribers so far.

Through venture capital firm Detroit Venture Partners, the former NBA star has invested in more than a dozen early-stage tech companies. Its most recent stakes include augmented and virtual reality marketing platform Marxent, online curriculum platform GingkoTree and bot detector Are You Human.

In January 2016, Magic Johnson Enterprises contributed to $3.25 million in seed funding for diversity hiring platform Jopwell.

The comedian dipped her toe into investment waters with Stamped, an app started by ex-Google employees. It lets users review and track all of their favorite things, from restaurants to music. In 2012, Yahoo purchased the start-up for $10 million.

In 2014, DeGeneres teamed with Warner Bros. for the firm Ellen Digital Ventures. The company has since launched two games -- Psych! And Heads Up! -- plus the family-friendly video destination EllenTube, and Ellen's Dance off, created from an investment and partnership with music competition app Chosen.fm.

Ashton Kutcher's Dude Where's My Car? doofus act was just that, an act.

Whip smart (he did major in biochemistry after all), savvy and with an instinct for what's hot, the actor's portfolio of more than 70 investments reads like a Who's Who of startups: AirBnb, Spotify, Uber, Flipboard, Skype Pinterest, Shazam, Foursquare, Warby Parker, Fab and mattress maker Casper, to name a few.

His A-Grade Investments, which he co-founded with Guy Oseary and Ron Burkle, is a respected and in-demand venture capital fund.

One of Kutcher's earliest successes was sinking an undisclosed sum into Skype, which Microsoft purchased two years later for $8.6 billion. Since then, he's only increased his knowledge and skills and is considered a Silicon Valley insider (and not just because he portrayed Apple co-founder and visionary Steve Jobs in a film).

The former supermodel started the Fierce Capital investment arm of her Tyra Banks Company to invest in early-stage startups and female-focused businesses.

So far she has invested in social shopping site The Hunt (which was later acquired by Pinterest), millennial career site The Muse, lockscreen app Locket (which was acquired by mobile shopping app Wish), and multiple rounds of video portal Videogram.

Unlike his showy and flamboyant turn as the Joker in Suicide Squad, the Oscar-winning actor has kept a relatively low profile in the tech world, despite making more than 40 investments.

He's had stakes in Reddit, digital health platform Headspace, food-lovers video network Nom, video collaborator Frame.io, Radius, Meerkat, Zenefits, Reserve and Wish.

Leto once cited one of his best investments as Nest Labs, which Google purchased for $3.2 billion in 2014. The actor and musician has also launched three of his own companies: social media management and digital marketing company The Hive, VIP fan experiences company Adventures in Wonderland, and online platform VyRT.

Singer, tween heartthrob, and now, venture capitalist. The pop star, who was discovered through his YouTube videos, has appropriately been drawn to investing in social media.

Bieber made his first investment in 2009 (although he won't divulge the startup's name) and since then has quietly backed at least a dozen companies. Among the companies we do know about are music service Spotify, ratings app Stamped and Tinychat.

He's perhaps best known for his $1.1 million investment in selfie and comedy app Shots, which he uses frequently to share photos of himself on Twitter. The app boasts more than 5 million users and has raised $15.2 million in funding.

In 2015, Madonna joined Jay-Z and multiple other musicians in signing a co-ownership declaration for the subscription-based music streaming service Tidal. Although critics panned what was seen as a millionaires' cash-grab, more than 3 million subscribers have paid for the service to date.

True to her dancer roots, Madonna also co-founded the startup digital network DanceOn, which promotes the work of dance content creators. Its biggest success story is the viral hit "Watch Me (Whip/Nae Nae)," which already had YouTube traction of its own. DanceOn's hand-picked influencers made their unofficial videos for the song, launching more than 250 million views in three months.

Towering basketball legend Shaquille O'Neal began his love of tech by investing in pre-IPO Google stock in 2004. The value of that stock has multiplied by six times.

His interest in startups began when he retired from the NBA. In fact, he announced his retirement using the video-sharing startup Tout, for which he received a seat on the advisory board and a small equity stake in the company.

And it looks like Shaq is attacking startup investing in earnest. In 2015, he backed online investment company Loyal3 for an undisclosed sum. He'll also join the San Franciso-based company's advisory board.

The rapper has invested in Reddit, stock brokering app Robinhood and the sports-chat app GameOn.

Then in 2015, Snoop decided to take the high road, so to speak. The marijuana aficionado created Casa Verde Capital to invest in pot-centric startups. The VC's first stake was for delivery service Eaze, aka Uber for weed.

All of this is part of The Doggfather's master plan: a lifestyle media site called Merry Jane that's a hub for all things pot. Snoop announced the launch of the platform at 2015's TechCrunch Disrupt.

The U2 frontman is the managing director and co-founder of private equity firm Elevation Partners, which has invested in Forbes, analytics company Marketshare, video game company BioWare/Pandemic Studios, online real estate facilitator Move, Dropbox, Yelp, and most famously, Facebook.

In 2009, the investment group spent $90 million for one percent of the social network when it went public. In 2015, the estimated return for that investment was $1.4 billion.

Multi-platinum hip-hop artist Nas has been leading a double life as a tech investor and has even befriended Andreessen Horowitz co-founder Ben Horowitz. The two have teamed up on a number of investments, including Genius and NationBuilder.

Through QueensBridge Venture Partners, Nas has also backed more than 40 companies, with more than half of them in startup. Some of the investments include SeatGeek, Robinhood, Lyft, Dropbox, Meerkat, ViralGains, Proven, and Casper.

On his own, he's made investments into the digital audio postproduction tool LANDR.

The rapper is too legit to quit Silicon Valley. Hammer was one of the first celebrity Twitter superstars and advises 10 tech companies regularly. Although his own startups -- DanceJam and WireDoo -- both failed, he's made some savvy and successful investments that include Square, Flipboard, Kiip and Bump Technologies, which allows smartphones to connect by being bumped together.

The former Black Eyed Peas frontman was an early investor in Twitter and owned a founding stake in Beats Electronics, which Apple acquired for $3 billion.

The former American Idol host may have failed with Typo, a keyboard device for iPhones that BlackBerry successfully sued for patent infringement, but that didn't scare Ryan Seacrest off tech.

Both privately and through his Seacrest Global Group, Seacrest has invested in Headspace, Stamped, FlightCar, the social media stars concert company DigiTour Media (in hopes of scouting emerging talent) and social impact network ATTN:.