The Nasdaq Stock Market is currently investigating issues with connectivity, particularly regarding its matching engine, which is affecting order acknowledgment. The exchange has provided limited details, but electronic exchanges use a matching engine to facilitate price discovery and match buy and sell orders. Orders sent using RASH FIX engine are currently not being acknowledged. Nasdaq continues to provide updates on the situation. This issue impacts the facilitation of price discovery and order matching, which are crucial aspects of the exchange's operation.