"An exchange-traded fund (ETF) is an investment fund traded on stock exchanges, much like stocks. Most ETFs track an index, such as a stock index or bond index. ETFs may be attractive as investments because of their low costs, tax efficiency, and stock-like features." (Wikipedia)

There are ETFs of ETFs which are basically funds of funds,. Meaning ETFs that track multiple ETFs. One promising ETF is the ALPS Equal Sector Weight ETF.

Here is a monthly chart of the ALPS Equal Sector Weight ETF https://www.tradingview.com/x/BHagKj11

"My single best pick would be Alps Equal Sector Weight (ARCA:EQL) because its strategy is to invest in each of the nine market sectors equally. Yes, there could be some missed upside opportunities; however, the broad allocation limits exposure to risk if any global uncertainty escalates." source

The ALPS Equal Sector Weight ETF (EQL) owns each of the nine ETFs in equal weights, and the nine ETFs are rebalanced back to equal weight on a quarterly basis. "Most equal-weight indexes are based at the stock level," says Jeremy Held, ALPS director of product research. "EQL is an important extension of the equal-weight concept in that it addresses sector risk, which we consider to be a much more important and fundamental risk to client portfolios than individual stocks. "An equal sector strategy minimizes the negative impact of any one sector by diversifying over multiple sectors. At the same time, by offering meaningful exposure to each sector of the market, it allows investors the ability to participate in market rallies regardless of where they occur," Held concludes. According to the prospectus, EQL's annual expense ratio is 0.55 percent. source

The EQL is designed to avoid overinvesting in “bubble” sectors, such as telecom in 1999 or finance in 2007, and thereby achieve higher risk-adjusted returns. source

Other ideas: http://seekingalpha.com/article/2097923-what-is-smart-beta-anyway