Plus500 is, above all, a trusted broker. Based in the UK, it holds the main licenses for financial instruments. It is notably in compliance with the regulations of the FCA or Financial Conduct Authority.
Plus500 is also publicly traded in London and is responsible for making regular financial reports to its clients. The funds deposited on the platform are, as a bonus, protected by the segregation of account. Even if the broker goes bankrupt, the traders are thus assured to receive their money.
Info : https://www.plus500.com/