On-Balance Volume (OBV)

OBV

Cumulative volume indicator that adds volume on up days and subtracts it on down days to reveal whether volume is confirming a price trend.

OBV_t = OBV_{t-1} + Volume_t (if Close_t > Close_{t-1}); OBV_t = OBV_{t-1} − Volume_t (if Close_t < Close_{t-1}); OBV_t = OBV_{t-1} (if Close_t = Close_{t-1})