amd radeon 580

I'm new to this and haven't done anything besides add memory to my computer so wanted to know - is it possible to add a 2nd graphics card? MY GPU now is Radeon RX 580. My motherboard is Microstar MS-7B48 I'm a day trader and my platform - thinkorswim - is having issues running with 4x - 4k...

I have an rx 580 with 4gb of vram, 8 gb ram and a ryzen 1500x cpu. sometimes at random moments while gaming my pc will just repeat the last seconds of audio output, my screen will scramble and show white lines. after that my pc stops outputting anything, no video no sound and doesnt take any...