A formula for pricing financial options. Its invention allowed a previously undreamed of precision in the pricing of options (which had hitherto been done using crude rules of thumb), and probably made possible the explosive growth in the markets for options and other derivatives that took place after the formula became widely used in the early 1970s. Myron Scholes and Robert Merton were awarded the Nobel Prize for economics for their part in devising the formula; their co-inventor, Fischer Black (1938—95), was ineligible, having died.