What must EU citizens do to purchase shares in companies across the EU?

To purchase shares in companies across the EU, citizens must be able to conduct financial transactions freely. This principle is rooted in the European Union's single market framework, which allows capital to flow freely between member states. The establishment of a unified market aims to create an environment where individuals and businesses can engage in investment activities without facing barriers based on country of origin.

This freedom ensures that EU citizens can take advantage of investment opportunities throughout the EU, fostering economic growth and cooperation among member nations. The ability to conduct financial transactions freely eliminates unnecessary complications, such as requiring permits or adhering to overly stringent regulations that might impede cross-border investments.

In contrast, the other choices present concepts that are not necessary for purchasing shares across the EU. Specifically, obtaining special permits from one’s home country or only investing in domestic companies would contradict the fundamental principles of the EU’s single market. Furthermore, while there are regulatory frameworks in place intended to protect investors and maintain market integrity, they do not impose strict prohibitions that would hinder the fundamental ability to invest across borders within the EU.