PowerColor has released two external graphics enclosures, the Mini and Mini Pro, exclusively for Mac users
Blackmagic eGPU now available exclusively on the Apple.com
You can now use an external graphics card with your MacBook Pro or iMac

You can now use an external graphics card with your MacBook Pro or iMac

Apple has announced support for external graphics cards on macOS High Sierra 10.13.4 or later.
Razer puts Intel's 8th-generation quad-core chip into the Blade Stealth, announces new Core V2 GPU dock

Razer puts Intel's 8th-generation quad-core chip into the Blade Stealth, announces new Core V2 GPU dock

Razer has now announced a more powerful version of the Blade Stealth with Intel’s latest 8th-generation Coffee Lake processors, so you should get some additional multi-tasking oomph. It also revealed an updated Core V2 external GPU dock that comes with functional and usability improvements.