Marshall, BRNguyen, NHVisaltanachoti, NZhu, J2024-10-022024-10-022024-09-20Accounting and Finance, ISSN: 0810-5391 (Print); 1467-629X (Online), Wiley. doi: 10.1111/acfi.133390810-53911467-629Xhttp://hdl.handle.net/10292/18091Brokers have access to order-flow data, which they can use to enhance their short-selling returns. However, New Zealand brokers also have a fiduciary duty to place their clients' interests before their own. We compare the short-selling returns and trading behaviours of brokers and institutional investors who predominantly focus on profit-making. Our results show no significant return difference between broker and institutional short sales and indicate that broker short sales are apparently to stabilise the market. Short selling is associated with improved market quality, and this improvement is more pronounced when brokers short sell more than institutional investors.© 2024 The Author(s). Accounting & Finance published by John Wiley & Sons Australia, Ltd on behalf of Accounting and Finance Association of Australia and New Zealand. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.http://creativecommons.org/licenses/by-nc-nd/4.0/38 Economics3502 Banking, Finance and Investment3801 Applied Economics35 Commerce, Management, Tourism and Services1402 Applied Economics1501 Accounting, Auditing and Accountability1502 Banking, Finance and InvestmentAccounting3501 Accounting, auditing and accountability3502 Banking, finance and investment3801 Applied economicsJournal ArticleOpenAccess10.1111/acfi.13339