Volume Profile displays the quantity of contracts, currency units traded or data ticks per price level.
Market Profile displays the quantity and indices of time periods where prices occurred per price level. Units are named TPO's, short for Time Price Opportunity. Market Profile is a charting technique by J. Peter Steidlmayer, a trader at the Chicago Board of Trade (CBOT), ca 1959-1985.
Volume is the quantity of contracts or currency units traded, data used in analytics to represent activity based on monetary value, inherently data is not available for all symbols and might be limited by scope of brokerage or trading venue.
Tick Volume is the quantity of data ticks, e.g., last order price updates, data used in analytics to represent activity based on data feed updates.
Change of chart timeframe and price level grid cause reinitialization. A minor price level grid change might cause significant distribution changes. Change between charts of which the current window is maximized reverts the then non-visible window's dimensions, i.e., height and price scale, causing reinitialization.
Distributions might be discarded and recalculated at high rates, e.g., scrolling chart without fixed price scale might cause the price level grid to change many times per second.
On initialization system resources are primarily utilized for processing of lower than chart timeframe period historical data.
By default highest quality datasets are compiled, i.e., using prices of lowest timeframe period historical data.
To improve performance use a dataset history plan other than quality or manually set history timeframe to a higher period, e.g., M15 opposed to M1 data rows utilize 15 times less system resources.
Inspect historical data coverage in the panel to specifically determine the lowest period data required for highest quality visualizations, i.e., visualization on high scale H4 chart might not require M1 data rows.
Other factors might be a large dataset range, high amount of segments, small price level size and/or small TPO period size. More specific to the terminal is the total activity, i.e., resource utilization, of all attached chart application instances and Market Watch symbols. For calculations of multiple attached indicators the possibility of delay by single thread operations, i.e., MetaTrader 5 utilizes a separate thread to operate indicators for each symbol. If historical data is not downloaded before attaching an indicator instance to a chart distributions will be discarded and recalculated for each time new data is received until set timeout.
Set files (.set extension) are to configure chart applications (e.g., type 'Indicator' and 'Script') they contain application input parameter settings. Set files can be used via the application's properties window 'Inputs' tab.
Templates (.tpl extension) are to configure charts they contain chart parameter settings including configurations of all applications attached to it. Templates can be used via the menu bar or context menu.
INI files (.ini extension) are to configure advanced or less frequently used settings and can be edited with a text file editor. For the Volume by Price Indicator they contain settings to configure custom user interfaces and dataset history plan, and can be used via the indicator's properties window 'Inputs' tab by file path as text input parameter values.
To improve accessibility and comply with third-party App Store policy changes respectively. The Volume by Price Indicator is now available as a single edition without feature limitations. Previously released editions are actively maintained as the current release having received Pro feature upgrades. To install or update open 'Terminal' (MT4) / 'Navigator' (MT5) window and select 'Market', then 'Purchased' and use the 'Install/Update' button.
"Market profile - Wikipedia" https://en.wikipedia.org/wiki/Market_profile
"INI file - Wikipedia" https://en.wikipedia.org/wiki/INI_file
"Program Running - MQL5 programs" https://www.mql5.com/en/docs/runtime/running
"Program Running - MQL4 programs" https://docs.mql4.com/runtime/running
"Templates and Profiles - MetaTrader 5 Help" https://www.metatrader5.com/en/terminal/help/charts_advanced/templates_profiles
"Templates and Profiles - MetaTrader 4 Help" https://www.metatrader4.com/en/trading-platform/help/chart_management/templates