The Time Series Forecast function displays the statistical trend of a security's price over a specified time period based on linear regression analysis. Instead of a straight linear regression trendline, the Time Series Forecast plots the last point of multiple linear regression trendlines. This is why this indicator may sometimes referred to as the "moving linear regression" indicator or the "regression oscillator."
Because a linear regression line is a straight line as close as possible to all of the given values, a Time Series Forecast does not exhibit as much delay as a Moving Average when adjusting to price changes. This is because the indicator is continuously "fitting" itself to the data rather than simply averaging them. Note that this type of prediction is purely mathematical as it is ultimately the equivalent of drawing a line through the recent points and projecting that line forward.
The Time Series Forecast at the beginning of a data series will not be defined until there are enough values to fill the given period.