Riding on the rising stock of his companies, business tycoon Gautam Adani is now the second richest person in Asia. With a net worth of $66.5 billion, nearly half of it accumulated in the past year, Adani outdid Chinese tycoon Zhong Shanshan by nearly $3 billion, according to the Bloomberg Billionaires Index. Reliance boss Mukesh Ambani, who went past Shanshan in February to become the richest Asian, maintains the top slot. His net worth stands at $76.5 billion. On the global billionaires list of Bloomberg, Ambani ranks 13, Adani is a notch below.