(Reuters) -Activist investor Blackwells Capital LLC wants exercise equipment maker Peloton Interactive Inc. to fire its chief executive and consider selling itself to a fitness or technology company, two sources familiar with the matter said on Sunday. The pandemic turned Peloton which offers stationary bikes and treadmills with livestreamed workouts from popular instructors into one of the market's hottest stocks, but the company's stock price has plummeted 84% in the last year...