(10)Furthermore, Article 18 of the FMIA requires stock exchanges to grant participants and market makers non-discriminatory and open access. FINMA ensures both during the authorisation process and on an ongoing basis that exchange rules comply with this requirement (see sections 3 to 5 of the SSX Rule Book in conjunction with the SSX Directive 1 and sections 3-5 of the BX Swiss Rule Book). Denial of access is only permissible on safety and efficiency grounds and subject to a stringent proportionality test (Art. 18 of the FMIA, 17 of the FMIO). Applicants who have been denied access may lodge an appeal with an independent appeal board (section 8 of the SSX Rule Book and section 15 of the BX Swiss Rule Book). Compliance of exchanges with Article 18 of the FMIA and Article 17 of the FMIO is subject to FINMA's supervision. The adoption of rules and amendments thereto require FINMA's ex ante approval, their implementation may be scrutinised by FINMA staff, audits, requests for information, or remedial action pursuant to Articles 24 ff. of the Federal Act on the Swiss Financial Market Supervisory Authority (‘Financial Market Supervision Act’, ‘FINMASA’).