The lone analyst with a sell rating on Fiserv Inc. ahead of the company’s crushing stock selloff says the writing was on the wall for months. For a large chunk of Wall Street, the fintech’s massive earnings miss was a surprise: Nearly 80 per cent of the analysts covering Fiserv had buy-equivalent ratings as of earlier this week. But Dominic Ball, a 26-year-old analyst at Rothschild & Co Redburn, had slapped a sell-rating on the company in April.On Wednesday, his skepticism was rewarded when the company’s sh ...