This paper investigates the dynamics of the factors of the Fama & French (1993) model using data from the UK financial market. Since financial markets are exposed to exogenous and endogenous structural changes due to the implementation of new regulative guidelines and/or the fluctuation of investors’ behavior or the unanticipated financial crises, my analysis is based on an econometric methodology that accounts for structural breaks and regimes shifts. According to the empirical results of the paper, although the functioning of the conventional risk premiums seems to adequately explain the cross-sectionality of share returns, there exists instability on the parameter set, which is associated with the fundamentals of the UK economy. Finally, the implications of these results shed much light on the contribution of the recent financial crisis into the informational efficiency of the UK financial market. Thus, although the current liquidity crisis is linked with unanticipated imbalances in the economic environment, it might have been a good opportunity for individual and institutional investors to revise their investing strategies, since the excess returns’ risk premia have reached more informative regimes. | Efficiency of the UK stock exchange
