As equity markets grind higher and investors complain about the absence of value, they continue to flock toward cheap and efficient exchange-traded funds (ETFs). Money directed to equity ETFs grew 13% in 2016, pushing the assets under management to $2.4 trillion in the U.S. alone.

While the ETF growth stampede continues, seemingly ignoring valuations in some cases, an ocean of value is being ignored among the ETF's grandparents: the venerable closed-end fund (CEF).

I've always had a soft spot for the good old CEF. They tend to fly under the radar. So, before we go shopping, here's a little historical background.