Congress leader Rahul Gandhi on Thursday alleged that Prime Minister Narendra Modi and Home Minister Amit Shah were “directly involved” in what he described as the “biggest stock market scam” in which retail investors lost Rs 30 lakh crore, and demanded a joint parliamentary committee probe into it. Addressing a press conference here, he also said stock markets rose after “fake” exit polls and then crashed the day Lok Sabha polls votes were counted on June 4.