Investors may want to boost their exposure overseas."Home bias is about as bad as it's ever been in the United States. The average investor has far too much of their money sitting in the United States," ETF.com's Dave Nadig told CNBC's "ETF Edge" this week.Nadig, the firm's president and director of research, delivered his concerns during a record week on Wall Street. The Dow, S&P 500 and Nasdaq gained another one percent this week. Meanwhile, the iShares MSCI Emerging Markets ETF gained almost 3%. As of Fr ...