These give the owner of the option the right to buy the futures contract within a certain time frame at a preset price.

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It has an exclusive option to repurchase its rights to the three drugs for a preset price, which it will likely do if the clinical trials succeed on its cholesterol-lowering drug, called 301012.

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But they have proved unpopular with some energy suppliers, which say basing them on the difference between the actual market price and a preset, guaranteed price, is overly complex.

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The preset repurchase price gives Symphony and its co-investors an average return of 32% a year.

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