It is very common to encounter commercial law regulations designed towards encouraging shareholders to make long-term investments in different jurisdictions in response to the issue of short-termism. Until a few months ago, EU Shareholder Rights Directive was seen as the most effective step, which was put into effect as of 3 September 2020, as regards the encouragement of long-term shareholder engagement. However, when the latest developments are considered, a new era has just started in Spain with Law No. 5/2021, which entered into force on 3 May 2021, regarding the duties and responsibilities of managers to increase shareholders’ long-term loyalty to listed companies by complying with the modifications envisaged by Directive 2017/828. This study, in light of what has been covered hitherto, examines the amendments (reform) brought by Law No. 5/2021 as well as evaluating its possible effects on the functioning of company law.