I can't see anything stopping the markets. With the world so inter-connected, tons of people looking for clues for the next black swan. Maybe a war? Maybe a bank default ( tho that won't trigger a crash )? Maybe Italy's election to an exit of the euro zone?
Markets are all time high, finding the right counters to invest is increasing difficult.
For now, bonds, utilities and energy sectors are my personal picks, with reduced position. Moving more to cash. Now more then ever, the investment world is crowded with so many people putting in cash, and if history was a lesson, consensus are usually wrong.