code: def B2(self):
      ''' 量縮價不跌 '''
      return self.a.stock_vol[-1] < self.a.stock_vol[-2] and self.a.PUPTf B2(self):
      ''' 量縮價不跌 '''
      return self.a.stock_vol[-1] < self.a.stock_vol[-2] and self.a.PUPTY
docs: 量縮價不跌