Modified Renko brick size from tick inputs

Two inputs set the brick size

A modified Renko construction follows an explicit bar-creation routine instead of a platform default preset. A spreadsheet construction of modified Renko bars exposes only two user inputs: the number of instrument ticks per brick and the instrument tick size.

The brick size, also called the range value, is the product of ticks-per-brick and instrument tick size. When the sheet stands in for a platform default, equity instruments are assigned a tick size of 0.01 and forex instruments a tick size of 0.0001. The spreadsheet user must supply instrument tick size manually because a worksheet does not auto-assign that increment the way a dedicated charting platform does.

Class modules write the brick series

Behind the two inputs sit two custom class modules: one that represents individual bars and one that creates, stores, and manipulates the bar collection. A reusable bar record stores one completed brick and can be collected, updated, and written back to the sheet. The working list of completed bricks grows as new price movement qualifies.

A user-defined array function is the main construction line. It builds bricks through those class routines and writes the finished series back to the sheet. Inspecting the construction code requires opening the spreadsheet's macro editor, which may first need trust access to the VBA object model enabled.

Public tick history is scarce

Free public forex tick history is described as scarce. One- and five-minute ticks are generally not offered for free beyond the prior 24 hours, some sources offer four-hour ticks as old as three months, and many offer end-of-day bars spanning several years.