Up/Down Volume Ratio (UDVR)
The Up/Down Volume ratio compares the representation of buyers vs. sellers over a period of time. The assumption is that if a stock closes UP for the day, the attributable volume was induced by buying pressure and thus the stock is under accumulation. Conversely, if a stock closes DOWN for the day, the trading activity is deemed to be selling induced, a sign of distribution. Up/Down ratio is calculated by creating a ratio of the volume on days when price increased to volume on days when price decreased.