Hi Tovim,
You can see the detail description from the book "Analysis of Time Series Structure", Nina Gonyaldina et. al. There will be explained the methodology of SSA, SSA forecasting and detection of structural change. Here what i found during the study.
Basic SSA is useful to detect the trend of a time series, smoothing data, noise removal, seasonal harmonic extraction, cycles extraction (different frequencies), extraction periodicity (with different amplitude), evaluate time series structure (trend and periodicity). Using window length we create trajectory matrix, decompose them using singular value decomposition (SVD), and grouping them based on selected components. One thing to be highlighted is the SVD values will be changes at any time we add new data, since all eigen values and eigen vectors will change and depend on its data series, hence we can't expect that the result will not repaint. That is why ssa indicator is always repaint for any new data.
I already checked the ssa indicator available on MT4 has cover only basic ssa above, the missing part (available on caterpillar-ssa) is the forecasting future ssa values (using LRF) and the change point detection.
See the previous post that showing simple forecasting ssa, I made it using matlab, still develop to evaluate it for market data on NST using walk forward.