If you mean broker sites affected by Internet Positif, you could try to find alternative links from the broker you use. Usually, in addition to .com, brokers will also provide access through various web addresses such as idn...com, .net, .org, etc.
Or if there are no trusted alternative links, you can install a VPN on your internet connection, or you can also use a proxy. However, using a proxy is a bit risky if used to log in with your identity. There are usually also special extensions provided by your internet browser to open sites that are blocked, such as the "browsec" extension in google chrome.
For a more complete solution on unblocking websites, you can read it on this page.
Hopefully this helps.