밴드위드(Band Width) 매수신호/차트설정 및 조건검색식 https://youtu.be/32WBi8ESVRA 수식1 : a=(BBandsUp(30,1.5)-BBandsDown(30,1.5)) / BBandsC(30,1.5); valuewhen(1,crossup(a,0.1),c) 수식2 : a=(BBandsUp(20,2)-BBandsDown(20,2)) / BBandsC(20,2); valuewhen(1,crossup(a,0.1),c)