Twitch is growing at a rapid rate, and as their ongoing work to make Twitch more secure, they are updating the website to be served over HTTPS. Moving forward, this will let them build more seamless experiences across the site, like improving the ways you access your Settings and Payment options.
They are approaching the transition to HTTPS in stages, applying the update first to most of their page content, static content, Chat, and Whispers, and eventually rolling it out to live and recorded video.
If you have any questions about the transitions, or see any warnings from your browser, head over to the HTTPS FAQ on help.twitch.tv.
via Twitch Blog
