dollar
弗 is used in modern Japanese almost exclusively as a phonetic shorthand for the dollar currency sign, derived from its visual resemblance to a dollar symbol with two vertical strokes.
弗 originally depicted an arrow bound with a cord, representing negation or correction in classical Chinese. Its modern Japanese use for 'dollar' is a phonetic borrowing based on visual similarity to the dollar sign.
The two vertical strokes with a curving horizontal line look like a stylized dollar sign: 弗 is the kanji dollar.
For フツ, imagine a dollar bill fluttering down: the sound 'futs' mimics the fluttering motion, and フツ is the reading for the dollar kanji.