The iShares S&P 500 Index (ETF) (NYSE ARCA:IVV) zig-zagged with no certain direction for the first part of the year, gaining just over 3% during this somewhat volatile period. The index sits right above support at the 50-day moving average. Holding that level while also breaking through the 2120 level will be key to the direction of the market in the coming weeks.

The iShares S&P 500 Value Index (ETF) (NYSE ARCA:IVE), which consists primarily of US large-cap value stocks in the financial services, industrial, and consumer cyclical industries, tend to have lower price to earnings ratios and higher dividend yields than the market as a whole. The value index has been out of form this year, having slightly underperformed vs the S&P 500 while also seemingly forming a dreaded triple-top. The index is up 1.49% YTD.

The iShares S&P 500 Growth Index (ETF) (NYSE ARCA:IVW), which consists primarily of US large-cap growth stocks in the tech, healthcare, and energy industries, tend to have higher earnings growth rates, higher earnings multiples, and little or no dividend yields. Growth stocks have been the better bet so far in 2015, as the index is ahead of pace set by the S&P 500, returning 4.27% YTD.

A short-term trend of growth stocks outperforming value stocks has emerged. Over the longer term, you can see the shift from value stocks to growth stocks occurring in mid-2013.

While the iShares MSCI EAFE Index Fund (ETF) (NYSE ARCA:EFA), a global developed market index that encompasses Europe, Australasia, and the Far East, had significantly underperformed versus the S&P 500 in 2014, that has not been the case this year. The EAFE Index outperforming the US markets by a wide margin so far this year, gaining 10.54%, while also getting above both moving averages and forming a short-term uptrend line.

The iShares MSCI EAFE Value Index (ETF) (NYSE ARCA:EFV) consists primarily of low P/E international large-cap value stocks in the financials, energy, and communications industries. Like the US markets, international value stocks are also underperforming growth stocks of late, returning 9.50% YTD. The chart also looks a bit more negative than its growth counterpart, as the 50-day MA just recently crossed over the 200-day MA in what is known as a Golden Cross. That transition happened in March for the growth index.

The iShares MSCI EAFE Growth Index (ETF) (NYSE ARCA:EFG), which consists primarily of high-growth international large-cap growth stocks in the industrial, healthcare, and consumer cyclical industries, has outperformed compared to the value index. The index is up 10.94% YTD.

Over the long term, a shift from value stocks to growth occurred in late 2014.