The recent action in closed-end funds has been so puzzling that it requires a professional code-breaker to decipher it. Luckily, that was Richard Shaker's job before he started managing money. After retiring as chief of mathematical research for the National Security Agency in 1995, Shaker started Shaker Financial Services in order to focus his quant skills on trading closed-end funds. Based in Annapolis, Md., Shaker manages more than $60 million in assets, up from $3 million in 1995 and $24 million in 2002. At the end of March, Shaker's fund had a one-year total return of 23.4%, compared with 11.82% for the S&P 500 Total Return Index. For the prior three- and five-year periods, Shaker handily beat that index by 7.5 and 10.6 percentage points, respectively. TheStreet.com spoke with Shaker about the recent turbulence in closed-end funds. TheStreet.com: Lately we have seen a lot of sharp moves in the closed-end world. What is your take on the increased volatility?Shaker: Our strategy is to look for an individual fund that randomly moves above or below its typical discount level. Recently, we have seen entire sectors make a large, quick move in discounts, then just as quickly return to their pre-move levels. This is unusual. I've never seen it occur so dramatically. For example, we follow 10 funds that write options on their large-cap holdings as their basic strategy. I don't like the strategy and don't like the fact that they trade at very small discounts or premiums.