The National Stock Exchange will conduct a mock trading session for currency derivatives on July 14 ahead of implementing the self trade prevention check.A mock trading (contingency) session in the currency derivatives segment would be conducted on July 14, the exchange said in a circular.The bourse said the announcement is in continuation of its circular issued on June 15 regarding self trade prevention check, which is to be implemented on July 16.In a separate circular, NSE said it would conduct mock trading session in futures and options on July 14.