This CEO could lose more than any of the world's richest billionaires in 2018

It has been a tough year for social media giant Facebook – which has been reflected in CEO Mark Zuckerberg’s finances.

One year ago, Zuckerberg’s net worth was estimated at $74.5 billion, according to Bloomberg’s Billionaire’s Index. As of Tuesday, it had dropped to $55.5 billion – a whopping $19 billion decrease. Even if Zuckerberg were to only lose $15 billion, as predicted by Time Inc.’s Money Magazine, he is likely to see more of his net worth wiped out this year than any of the world’s 500 richest billionaires.

Amid a myriad of data privacy and security scandals, shares of Facebook – of which Zuckerberg is a major holder – have fallen nearly 19 percent so far this year.

While Zuckerberg’s loss is potentially the largest, he is not the only CEO to see their net worth drop in 2018 – which has proven to be a volatile year for the equity markets.

Alibaba co-founder Jack Ma, for example, saw his net worth drop to $36.7 billion from $45.6 billion, according to Bloomberg, an $8.9 billion decline.

Amancio Ortega, who founded Inditex fashion group – the parent company of retailer Zara – saw his net worth tumble to $61 billion, from $76 billion.

Google co-founders Larry Page and Sergey Brin lost $3.1 billion apiece.

Even legendary investor Warren Buffett lost about $4.4 billion.

Meanwhile, Amazon CEO Jeff Bezos – currently the world’s richest man – saw a $25 billion jump in net worth to $126 billion. Shares of the e-commerce giant have risen more than 31 percent so far this year. The world’s second-richest person, Bill Gates, also saw his worth increase – though slightly.

The U.S. stock market is on track for its worst December performance since 1931.