The stock market was strong last week in spite of the ongoing concerns in Europe. It is likely that this issue (Europe/Greece/Spain) is suffering from investor fatigue and in that case the markets should continue to be strong.
The best part of a bull market is the initial stages, while the average investor is sleeping.
This being said, the recent strength could be one big head-fake with the bear returning with full fury. In any case, the good sectors are starting to separate from the bad. So don't just jump on the bandwagon but be very selective.