Market Breadth Primer: Advance / Decline Ratio and Advance Issues Percentage Conversion
Different data feeds offer different favour of the advance decline data to their customers. However, not all trading platforms are capable of letting the users to conduct calculations directly from multiple data series. Hence, odd combinations of the advance decline data are often provided as a workaround for the traders. These vendor provided ratios may not be what you want but don’t worry, following are formulas for converting these numbers.
A = Advance Issues
D = Decline Issues
Advance Decline Ratio = A / D
Advance Issues Percentage = A / (A + D) * 100
Advance Decline Ratio to Advance Issues Percentage
Given R as Advance Decline Ratio,
Advance Issues Percentage = R / (R + 1) * 100
Advance Issues Percentage to Advance Decline Ratio
Given P as Advance Issues Percentage,
Advance Decline Ratio = P / (100 – P)
No magic here, just handy formulas derived from their definitions. In case your trading platform only provides you with the advance decline ratio but you like to work with advance issues percentage instead, use the formula above will give you what you need.