Zhang Yong and his wife Shu Ping, the founders of China's largest hotpot chain Haidilao, have become $6 billion richer this year, according to Bloomberg. Haidilao, popular for hotpot dishes featuring spicy broth and meat, saw its revenue grow 60% to $2.6 billion last year. The couple, who are Singaporean citizens, now have a net worth of $13.6 billion.