Idea of Bitcoin Icon
There is a circle with the letter B inside of it. The letter B has four tiny rectangles (all equal size), two on top of it and two on the bottom of it. By having these rectangles attached to the letter B, the letter appears to look like the US dollar sign - - $.
This page contains the Bitcoin vector icon, as well as variations of this icon in different visual styles, and related icons. All icons are in the flat vector style, however, differ by the line thickness, fill, and corner radius.