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. <b1>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.

While merchant bankers appear to have valued the Mundra Port stock conservatively, the market has given it a higher price as it is the only listed stock in India from the port and the trade zone sector.

"It is a fancied sector. There is a scarcity value attached to it,” said MAA Annamali of Akshaya & Co.

Another reason for the high valuation is because Adanis are estimated to be holding the largest 'land bank' — real estate still to be developed — in Gujarat.

The Rs-10 share of Mundra Port & Special Economic Zone Ltd, in which the family holds 81.3 per cent, which was sold at Rs 440 per share to the public, listed at Rs 770. At one point, it changed hands at Rs 1,050.

Gautam added $4.3 billion, (Rs 16,770 crore) to his personal fortune and the family fortune rose by $7.9 billion (Rs 30,810 crore).

"It is a satisfactory listing. The valuation may be a little higher at the current market price, but this a stock that would be preferred by long-term investors like pension funds and insurance companies,” said Deven Choksey of KR Choksey securities.