New Zealand Financial Markets Authority has issued its latest market cleanliness report, comparing NZX data from 2004 to 2025 and reporting continued minor improvements in insider trading indicators over the past two decades. The report points to a general trend of gradually declining insider trading, with overall stock market cleanliness described as fairly stable. Regular market cleanliness measurement is positioned as an aggregate view of market conduct that complements investigations into individual insider trading cases referred by NZ RegCo, the NZX’s oversight firm. The FMA reiterated that monitoring, detecting and deterring market abuse remains a priority and referenced recent enforcement outcomes, including the April 2025 sentencing of a former Heartland Bank Limited treasury accountant on three insider trading charges and the May 2025 Court of Appeal decision increasing the sentence in an earlier Pushpay-related case. The dataset now runs from 1 January 2004 to 31 December 2025 at daily frequency, using historical stock and index price data from Yahoo Finance and price-sensitive announcements from NZX Company Research, and covering both listed funds and equities.