N ational Stock Exchange (NSE) has withheld payment to a few beneficiaries of a freak trade by brokerage Emkay Global and may consider annulling these trades, said a few brokers aware of the development. The incident, which took place in early trade on October 5, caused trading to stop for 15 minutes after the Nifty tumbled over 15% within seconds. It also burned a Rs 51-crore hole in Emkay's pocket. In a recent letter to the trade's counterparties, the exchange has reportedly sought an explanation as to why the trades should not be annulled. Mumbai-based Inventure Growth & Securities and Ankit Financial Services are among the beneficiaries which confirmed having received NSE's letter. An email questionnaire to NSE asking if it had indeed sent out letters to the beneficiaries went unanswered. "...you and those of your clients on whose behalf the said trades have been executed are hereby called upon to offer your explanation as to why all or any ...