The DividendRank formula at Dividend Channel ranks a coverage universe of thousands of dividend stocks, according to a proprietary formula designed to identify those stocks that combine two important characteristics — strong fundamentals and a valuation that looks inexpensive. Tortoise Energy Infrastructure Fund ( TYG) presently has a stellar rank, in the top 10% of the coverage universe, which suggests it is among the top most "interesting" ideas that merit further research by investors.But making Tortoise Energy Infrastructure Fund an even more interesting and timely stock to look at, is the fact that in trading on Thursday, shares of TYG entered into oversold territory, changing hands as low as $40.0801 per share. We define oversold territory using the Relative Strength Index, or RSI, which is a technical analysis indicator used to measure momentum on a scale of zero to 100. A stock is considered to be oversold if the RSI reading falls below 30. In the case of Tortoise Energy Infrastructure Fund, the RSI reading has hit 29.0 — by comparison, the universe of dividend stocks covered by Dividend Channel currently has an average RSI of 45.4. A falling stock price — all else being equal — creates a better opportunity for dividend investors to capture a higher yield. Indeed, TYG's recent annualized dividend of 2.58/share (currently paid in quarterly installments) works out to an annual yield of 6.36% based upon the recent $40.57 share price.