  The possibility that price dynamics is affected by its distance from a moving
average has been recently introduced as new statistical tool. The purpose is to
identify the tendency of the price dynamics to be attractive or repulsive with
respect to its own moving average. We consider a number of tests for various
models which clarify the advantages and limitations of this new approach. The
analysis leads to the identification of an effective potential with respect to
the moving average. Its specific implementation requires a detailed
consideration of various effects which can alter the statistical methods used.
However, the study of various model systems shows that this approach is indeed
suitable to detect hidden forces in the market which go beyond usual
correlations and volatility clustering.
