It is critical to ensure that your data will not be leaked to any other parties. Thus, the availability of certificates, like the PCI DSS, serves as proof of the service's safety. Besides, the regulation of exchanges is also important. For example, CEX.IO:
Is officially registered in the UK;
Has a Money Services Business status in FinCEN;
Complies with the legal requirements of the countries where it functions;
In addition, the two-factor authentication, DDoS protection, and use of
multisignature Bitcoin addresses turn it into one of the safest crypto exchanges in the USA and around the globe.