How is Volume Profile calculated?

Volume Profile uses trade volume for stocks, and tick volume for indices/Forex. Since we don’t have historical tick data on TradingView yet, we use up/down volume instead of buy/sell volume and calculate VP based on a price direction inside bars: if close >= open, we take it as an Up Volume, if close < open, it's Down Volume.

Note that while building Fixed Range Volume Profile on a single bar, the close > open condition is used to calculate the Up/Down Volume.  

Depending on time resolution of a chart, data from various resolutions can be used in calculations of Volume Profile. When calculating Fixed Range and Visible Range, we alternately try resolutions from 1, 3, 5, 15, 30, 60, 240, 1D, until the number of bars in the time interval, for which VP is calculated, will be less than 5000. 

For Session Volume the following dependency on a chart resolution is adopted: 

Chart cycle

Time period of the bar used for VP calculation

1 - 51
6 - 155
16 - 3010
31 - 6015
61 - 12030
121 - 1D60