This paper deals with our recent results on the reduced instability of metallic supercooled liquid and the resulting bulk glassy alloys by paying attention to the following factors; alloy compositions, glass-forming ability, less unstable mechanism, computed simulations of glass-forming ability and glass formation range, atomic configurations and production techniques. As demonstrated in this review, the high reduced instability of metallic supercooled liquid has already opened up new basic science and engineering application fields and its importance is expected to increase more and more hereafter.