Hearing from your fund manager during turbulent times is critical to investors. And the managers of closed-end funds consciously try to stay in touch with their clients during those unsettling times.

"Getting the manager to document in bite-sized ways so that the financial advisors and clients can know that... is useful," says John Cole Scott, Chief Investment Officer of Closed-End Fund Advisors.

Although not as highly publicized or as well known as ETFs, closed-end funds have long been valued by advisors and investors as a tool for potentially boosting investment income.

With market yield still low and volatility returning this year, now maybe a particularly opportune time to consider adding closed-end funds to your portfolio and your clients' portfolios.

Want to learn more about closed-end funds? Check out TheStreet's webinar Why Closed-End Funds Could Deliver A Powerful Income Boost, sponsored by Nuveen.

Want to Buy $1 Worth of Stock for 90 Cents or Less? You can with certain so-called "closed-end" mutual funds - an often overlooked investment class. Click here to register for a free online video in which TheStreet's retirement expert Robert Powell and an all-star panel tell you all you need to know. The webinar is sponsored by Nuveen.