Five things to think about this week:

GOOD RUN 
-  Stocks have managed to extend their rally but potential hurdles, such as this week's U.S. non-farm payrolls, could prove increasingly hard to leap given valuations -- European stocks are trading at their highest multiples of earnings since May 2008 while the multiple for the S&P is the highest since mid-September 2008. If investors are to boost equity holdings -- which Reuters polls show already back to pre-Lehman levels -- it may require more concrete evidence of economic expansion, rather than just economic stabilisation, and signs that profit margins will be supported by revenue growth, rather than cost cutting.