After a stock market twister brought him and his brother Rajesh $4 billion in 20 minutes, Gautam Adani, the 45-year-old chairman of Adani Group, entered Forbes magazine’s exalted list of billionaires for the first time this year on Tuesday.

By the end of the day, on which Adanis’ latest venture Mundra Port & Special Economic Zone Ltd — a diversified conglomerate into everything from port operations to power trading to edible oils and commodity exports — listed on the stock exchanges, the brothers’ notional wealth had swelled by a staggering $8 billion. The first $4 billion came in the 20 minutes after the listing at 9.55 am.