non-business masters degree, impact on career

I am a 2+2 IBD->HF analyst (no B-school). If I took a year out of my career to pursue a random non-business masters degree, would that hurt my future career in public markets (other than opportunity cost of lost career progression)? For example, say I got a degree in something like math or public policy purely for reasons of personal interest - does this create risk or would this be tolerated? the fear would be that you don't get amazing grades or it signals lack of interest in public markets, for example.