Cairn floated on the stock market in 1989, when its shares were worth 192p. For years, the oil explorer bumbled along, seemingly confined to obscure mid-cap status. Then, last January, bang. Bill Gammell, the company's founder, revealed a major find in India and the shares rose, and carried on rising. Before the discovery in Rajasthan, in north-west India, they were 401p. Now they are 1450p. Today Cairn's promotion to the FTSE 100 index is confirmed, with a value of £2.3bn.