Source: Wikimedia Commons.

It's been a good year for investors. Since the beginning of 2013, the S&P 500 (^GSPC -0.95%) has soared more than 23%, leaving many portfolios plump just in time for the holidays.

Despite the broad-based success, however, some people have nevertheless done better than others. According to Bloomberg, the average increase for the 10 best-performing billionaires this year was a staggering $11.3 billion. That's more than the market capitalization of a full 164 companies on the S&P 500.

Billionaire

Change in Net Worth Year-to-Date (Billions)

Current Net Worth (Billions)

Bill Gates

$14.5

$77.2

Sheldon Adelson

$13.1

$35.8

Lui Che Woo

$11.9

$23.8

Warren Buffett

$11.8

$59.7

Ingvar Kamprad

$11.7

$51.4

Jeff Bezos

$11.4

$35.0

Mark Zuckerberg

$11.2

$23.4

Carl Icahn

$9.8

$25.7

Larry Page

$8.7

$30.1

Sergey Brin

$8.6

$29.8

Source: Bloomberg

Leading the way was Bill Gates, the founder and current-chairman of Microsoft (MSFT -1.30%) and the world's richest person. While many people assume that the lion's share of Gates' fortune is in the software company's stock, which is up 39% since the beginning of the year, the reality is that this accounts for only a fifth of his fortune -- though he's still one of Microsoft's largest shareholders, with an estimated 4.8% stake in the company. His remaining grubstake is tied up in Cascade Investment, a closely held investment company that has large positions in AutoNation and Canadian National Railway, among others.

Following closely behind Gates was Sheldon Adelson, the founder and largest shareholder in Las Vegas Sands (LVS -0.73%), the world's biggest casino company with operations in the United States, Macau, and Singapore. Given that the majority of Adelson's fortune is tied up in Las Vegas Sands stock, of which he owns 52.3% of the outstanding shares, it should come as no surprise that his performance this year comes on the heels of a 55% improvement in the company's share price.

Beyond these two titans, the top 10 list is dominated principally by technology giants. Jeff Bezos of Amazon.com is sixth, followed by Facebook's Mark Zuckerberg at seventh, and Google's Larry Page and Sergey Brin round out the list. Additionally, famed corporate raider Carl Icahn got a not insignificant boost from his positions in both Netflix and Apple, the former of which he's since trimmed for a purported gain of $825 million.