The National Stock Exchange’s planned initial public offering is set to unlock the value of long-term investments for a group of backers including Morgan Stanley, Temasek Holdings Pte. and State Bank of India.Among the biggest beneficiaries is SBI, which is selling 24.75 million shares. It stands to gain about 50 billion rupees ($529 million), based on the grey market price of 2,055 rupees a share on unlisted stock trading platform sharescart.com and its average acquisition cost of 80 paise apiece. That’s an almost 2,568-fold gain for the stake SBI acquired between 1993 and 1999 and does not include the increase in the value of its remaining holding. Other founding shareholders, including Stock Holding Corporation of India Ltd., General Insurance Corp. of India, New India Assurance Co. Ltd., National Insurance Co. Ltd. and Oriental Insurance Co. are also in line for sizable windfalls — as much as 6,422 times returns for the last three. Stock Holding Corp., which is selling about 11 million shares, acquired much of its stake at a cost of 46 paise per share and is on track for 4,467-fold returns based on the grey market price.Bloomberg NSE IPO set to deliver massive windfall for investors Many investors have been seeking an exit since NSE, the operator of the world’s busiest derivatives market, first attempted to go public in 2016 with a plan that was derailed by regulatory and legal hurdles. The pressure has built as NSE’s value soared over the past decade with India’s capital markets expanding and retail participation surging. The exchange now dominates domestic equity derivatives trading and has emerged as one of the world’s largest exchanges by contracts traded. Among international investors, Singapore investment company Temasek Holdings Pte. plans to sell about 11.25 million shares. It acquired NYSE Euronext’s 5% stake in NSE in 2010 for more than 7.8 billion rupees and the grey market implies an about 33-fold increase in value since then, making it one of the most successful financial sector bets in India. Morgan Stanley’s return is on track for about 31 times. In comparison, the benchmark Nifty 50 stock index has risen 4.61 times since 2010.For long-time shareholders, the IPO is more than just a liquidity event. It represents the end of years of uncertainty and provides a rare opportunity to monetise investments that have generated extraordinary paper returns while remaining largely illiquid. Even shareholders not participating in the offering stand to make gains. Life Insurance Corporation of India is the biggest shareholder, with a stake of almost 11%. While LIC will not be selling any shares in the offering, the company, which was among the first shareholders to subscribe to NSE’s shares in 1992, is set for a sharp revaluation of its ownership.