The roller-coaster sideways movement of the SPX for 2015 will likely persist until, at least, the September Fed meeting, when markets are anticipating the first rate hike. Until then, we may continue to see failure of (sustainable) breakouts in either direction.
If we see a bearish moving average Death Cross form on the World Market Index (as appears imminent soon on the Daily chart below), this would confirm a weakening global economy and would likely drag the U.S. markets down, as well -- possibly, before the September Fed meeting. This is one chart to keep an eye on, as well as China's Shanghai's Index.