Getty / David RyderAmazon CEO Jeff Bezos had a tough year.Wealth-X just announced its list of the biggest losers this year, proving that even the wealthiest hit rough patches.
Russian gas mogul Leonid Mikhelson lost the most, with over 40% of his fortune slipping away between Russia's struggling economy and weak oil prices.
Here are the billionaires who lost the most in 2014:
1. Leonid Mikhelson lost $7 billion.
Mikhelson, CEO of Russian gas company Novatek, lost nearly 41% of his $17 billion fortune this year, leaving his current wealth at around $10 billion. His losses stem from a number of factors, including the decline of Russian currency, weak oil prices, and economic sanctions placed on Russia by Western nations in light of the Russia-Ukraine conflict.
2. Masayoshi Son lost $5.9 billion.
Though he remains the richest man in Japan, the CEO of SoftBank, Asia's top Internet and telecommunications corporation, lost nearly $6 billion this year. Losses from Sprint, which SoftBank purchased last year, dragged down the company's overall earnings this year.
3. Lui Chee Woo lost $5.5 billion.
Chinese casinos struggled overall this year, and Galaxy Entertainment Group, which Woo owns, saw a 20% drop in revenue. Despite earning a strong $8.3 billion in 2013 as gambling surged last year, Woo ended this year with a $5.5 billion loss instead.
4. Jeff Bezos lost $5.5 billion.
As Amazon shares shares continue to drop - down 28% in 2014 - Amazon is predicted to lose an estimated $40.5 billion this year, according to Bloomberg. Bezos's personal wealth took a $5.5 billion hit as well, but the founder remains confident in Amazon's recovery.
5. Sheldon Adelson lost $5.2 billion.
It was a tough year for casino mogul Adelson, who is the CEO of the Las Vegas Sands Corporation. In addition to his personal monetary losses, hackers effectively shut down a major Las Vegas casino of Adelson's in February, stealing customers' Social Security Numbers and clearing hard drives.
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.