The Australian Securities & Investments Commission has filed proceedings in the New South Wales Supreme Court against Macquarie Securities (Australia) Limited, alleging repeated and systemic misleading conduct through incorrect short sale reporting to a market operator over more than 14 years. ASIC says the case is its first enforcement action focused on short sale reporting. ASIC alleges that between 11 December 2009 and 14 February 2024 Macquarie Securities failed to correctly report the volume of short sales by at least 73 million, and estimates the total misreported activity could be between 298 million and 1.5 billion short sales, driven by multiple systems-related issues that in many cases went undetected for over a decade. The alleged misreporting affected data for at least 321 securities, with ASIC alleging published short sale volumes were, on average, inflated or deflated by about 12 per cent per impacted security and in some cases by 50 per cent or more; separate allegations cover incorrect Regulatory Data reporting for 633,680 orders submitted between 16 November 2022 and 21 March 2023. ASIC is seeking penalties and orders for an independent review and assurance over the firm’s regulatory reporting systems, controls and supervisory procedures.