Before revision:  We investigate the model and show that the  market is nearly efficient on timescales shorter than one day , adjusting quickly to incoming news, but is inefficient on longer timescales, where news may have a long-lasting nonlinear impact on dynamics  attributable to a feedback mechanism acting over these horizons.
After revision:  We investigate the model and show that the stock market is nearly efficient on timescales shorter than one day , adjusting quickly to incoming news, but is inefficient on longer timescales, where news may have a long-lasting nonlinear impact on dynamics attributable to a feedback mechanism acting over these horizons.