Michael Coscia is no one’s idea of a 21st-Century Wall Street wizard. Coscia has become the unlikely poster child for the market crime of the moment: spoofing, a kind of electronic pump-and-dump scheme that traders use to profit at others’ expense. “The world of electronic trading is best understood by thinking in terms of the pit,” said Robert Webb, a finance professor at the University of Virginia. “We can mislead ourselves into thinking it’s something beyond human comprehension.”