The volume point of control indicator is based on the concepts and ideas of market profile, and out simply is the represenation of volume price and time on the Y axis of the price chart. The introduction of time then creates the volume histogram which relates directly the those short and longer periods of congestion which then create the low volume and high volume nodes accordingly.
The heaviest volume on the chart is denoted by the volume point of control which acts as the fulcrum of the market where price is in agreement and so congests. Once price disagreement is in play the price action then develops away from the VPOC and approaches the high and low volume nodes which then signal the likely price action, with low volume nodes offering little opposition to price, and high volume nodes signalling potential congestion.