Bill Gates dumped a huge amount of Microsoft stock this year

Bill Gates topped a list of the biggest insider sellers, which was dominated by the big names in tech.

Gates sold more than $717 million of Microsoft stock this year, according to Sqoop.com, and he wasn't the only one to turn his equity into cash.

Google co-founders Sergey Brin and Larry Page dumped more than $1 billion of their company stock between them, while former Twitter CEO Evan Williams sold $275 million of shares in the company he helped set up.

Here's the list of the top 10 insider sellers as ranked by Sqoop:

Tech insiders hold four spots on the top 10 list.

Most of the big sellers Sqoop found were former executives who now work at investment companies managing other people's money, which were removed from the final list.

"Once you weed out the Wall Street insiders on the list like Goldman, Thomas H. Lee, Madison Deerborne, and Welsh Carson, the list narrows quickly to fewer than 20 individuals out of the top 200 we examined," Sqoop's Bill Hanke's said.

Company insiders can sell off stock as long as they inform the market and only use information available to other investors to make their decision.

17 companies sold off more than a $1 billion in stocks through May of this year and the 40 largest sellers Sqoop compiled made a little over $50.7 billion in total.