SSgA closes international ETFs,

State Street is shutting down 19 ETFs, overwhelmingly in the international space. Funds being shut down include smart beta and currency hedged funds. In 2016, 130 ETFs closed. In 2017 the number sits at 50 as of June.

ETFs threaten liquidity: BoA

ETFs' surging popularity could lead to a liquidity problem, Bank of America has warned. As ETFs take up stocks, stocks become overvalued and less available. The danger is particularly pronounced during a downside.

How do you build an ETF-heavy portfolio?

How do you construct a portfolio to avoid bad emotionally-charged decisions? One, use lots of benchmarks - as ETFs do - such as the S&P 500. Two, always ALWAYS diversify. Three, have tactical allocations that provide a small release for emotional investments.