The 25 richest tech execs in the U.S.

Net worth: $5.9 billion

Change from 2017 ranking: +11

Net worth in 2017: $5.1 billion

Kalanick's spot in the Forbes 2017 list dramatically dropped when Uber essentially imploded, and the co-founder was forced out of his role as the company's CEO. Kalanick has since taken charge of a small real-estate startup and made up some ground in this year's rankings.

Net worth: $6.3 billion

Change from 2017 ranking: +274

Net worth in 2017: $2.2 billion

Dorsey made one of the biggest leaps up this year's list, thanks to shares of Square — a mobile payments company — rising exponentially in the past year.

Net worth: $6.4 billion

Change from 2017 ranking: +104

Net worth in 2017: $4.5 billion

The CEO of software company Salesforce most recently made headlines when he and his wife bought Time Magazine for $190 million.

Net worth: $6.6 billion

Change from 2017 ranking: +77

Net worth in 2017: $4.4 billion

Since Huang founded Nvidia in 1993, the company has profited from producing graphics cards for PCs and computer gaming.

Net worth: $7.3 billion

Change from 2017 ranking: -13

Net worth in 2017: $8.3 billion

Soon-Shiong is a huge player in the biotech industry and is credited with inventing the cancer drug Abraxane.

Net worth: $7.9 billion

Change from 2017 ranking: +28

Net worth in 2017: $5.8 billion

KPCB has been one of the largest VC firms investing in tech, and has backed giants such as Google, Netscape, Amazon, and Electronic Arts. Doerr and Kleiner Perkins both made headlines in 2015 when the firm went to trial in a gender discrimination lawsuit.

Net worth: $8.9 billion

Change from 2017 ranking: -4

Net worth in 2017: $8.9 billion

SAS software is used by more than 83,000 companies around the world. The company's headquarters is located in North Carolina, where Goodnight himself grew up.

Net worth: $9.4 billion

Change from 2017 ranking: +16

Net worth in 2017: $7.5 billion

The co-founder is the namesake for Moore's Law, which has widely been used to (pretty accurately) predict the evolution of computers — that the amount of computing power possible would double every two years or so, even as computers have become smaller and cheaper.

Net worth: $9.6 billion

Change from 2017 ranking: +1

Net worth in 2017: $9.6 billion

Koum sold his popular messaging app to Facebook in 2014 for $19 billion, and announced this April he'd be leaving his role to explore life outside of technology.

Net worth: $9.6 billion

Change from 2017 ranking: +190

Net worth in 2017: $7.5 billion

Duffield also co-founded PeopleSoft, which sold to Oracle in 2005. Workday, which provides companies with human resources and financial software, went public in 2012 and is now in direct competition with Oracle.

Net worth: $10.8 billion

Change from 2017 ranking: -14

Net worth in 2017: $15.8 billion

Ergen resigned as Dish Network's CEO at the end of 2017. The satellite network has steadily been losing subscribers as more viewers turn to streaming services such as Netflix and Hulu.

Net worth: $10.9 billion

Change from 2017 ranking: -11

Net worth in 2017: $13.6 billion

Moskovitz left Facebook back in 2008, but he made most of his money when the social network went public in 2012.

Net worth: $11.6 billion

Change from 2017 ranking: +10

Net worth in 2017: $9.6 billion

Omidyar became a billionaire just three years after he launched eBay in 1995. Since then, Omidyar has been an active journalism advocate and founded First Look Media, parent company of The Intercept.

Net worth: $14.4 billion

Change from 2017 ranking: +2

Net worth in 2017: $12.6 billion

By the time Schmidt left his position atop Google in 2011, the company had grown to 32,000 employees and $38 billion in revenue. Schmidt also served as executive chairman at Google's parent company, Alphabet, before he stepped down in January.

Net worth: $19.6 billion

Change from 2017 ranking: -3

Net worth in 2017: $20.8 billion

When he isn't busy trolling the SEC or getting a little high during interviews, Musk is shaking up the transportation industry at the two companies he founded — electric car maker Tesla and rocket company SpaceX.

Net worth: $20.3 billion

Change from 2017 ranking: +1

Net worth in 2017: $20.6 billion

Allen announced earlier this week he was re-diagnosed with non-Hodgkin's lymphoma, almost 10 years after he beat the cancer the first time. The Microsoft co-founder also owns two sports teams in the Northwest — the Portland Trail Blazers and Seattle Seahawks — and has a stake in the Seattle Sounders.

Net worth: $27.6 billion

Change from 2017 ranking: +2

Net worth in 2017: $23.2 billion

The tech exec announced earlier this year that Dell Technologies would be going public after it had turned private five years earlier. Dell also owns a controlling share in the cloud software VMware.

Net worth: $42.3 billion

Change from 2017 ranking: +1

Net worth in 2017: $33.6 billion

Ballmer left Microsoft in 2014 after serving as CEO for 14 years. In an interview last year with Business Insider, the billionaire said his favorite part of being retired was having time to play golf.

Net worth: $52.4 billion

Change from 2017 ranking: +1

Net worth in 2017: $43.4 billion

The president of Alphabet holds the title of America's richest immigrant (he was born in the then-Soviet Union). Brin once headed Google's moonshot factory called "X," where he spearheaded the launch (and failure) of Google Glass.

Net worth: $53.8

Change from 2017 ranking: +3

Net worth in 2017: $44.6 billion

Page is known as an introvert, and reportedly has traded a life in the spotlight for privacy on a Caribbean island he owns. He also is invested in multiple flying car projects.

Net worth: $58.4 billion

Change from 2017 ranking: No change

Net worth in 2017: $59 billion

Oracle's biggest growth came during the 1990s dot-com boom, as new companies relied heavily on its software for their databases.

Net worth: $61 billion

Change from 2017 ranking: No change

Net worth in 2017: $71 billion

A net worth loss of $10 billion is small potatoes to Zuckerberg. But Facebook's stock has been a roller coaster ride, from the Cambridge Analytica scandal to recent news that 50 million Facebook accounts were hacked.

Net worth: $97 billion

Change from 2017 ranking: -1

Net worth in 2017: $89 billion

Gates held the No. 1 spot on Forbes' wealthiest list for 24 consecutive years, but the king has been dethroned. It's not like Gates isn't still making money. But while he's putting time and money into the Bill & Melinda Gates Foundation, the new No. 1 hasn't been quite as philanthropic.

Net worth: $160 billion

Change from 2017 ranking: +1

Net worth in 2017: $81.5 billion

After Jeff Bezos set a record earlier this year as the richest man in the world, it's no surprise the Amazon CEO has taken the No. 1 spot from Gates. Even though Bezos' e-commerce giant is regularly criticized for poor working conditions in its warehouses and low pay wages for employees (Amazon recently responded to its critics by more than doubling its minimum wage to $15), Bezos managed to almost double his net worth in a single year.

Check out the rest of Forbes' 400 list here.