Looking at the universe of stocks we cover at Dividend Channel, on 5/16/13, Atmos Energy Corp. ( ATO) will trade ex-dividend, for its quarterly dividend of $0.35, payable on 6/3/13. As a percentage of ATO's recent stock price of $44.19, this dividend works out to approximately 0.79%, so look for shares of Atmos Energy Corp. to trade 0.79% lower — all else being equal — when ATO shares open for trading on 5/16/13.Below is a dividend history chart for ATO, showing historical dividends prior to the most recent $0.35 declared by Atmos Energy Corp.: In general, dividends are not always predictable; but looking at the history above can help in judging whether the most recent dividend from ATO is likely to continue, and whether the current estimated yield of 3.17% on annualized basis is a reasonable expectation of annual yield going forward. The chart below shows the one year performance of ATO shares, versus its 200 day moving average: Looking at the chart above, ATO's low point in its 52 week range is $32.20 per share, with $44.88 as the 52 week high point — that compares with a last trade of $44.26. According to the ETF Finder at ETF Channel, ATO makes up 1.61% of the High Yield Equity Dividend Achievers Portfolio ETF ( PEY) which is trading up by about 0.3% on the day Tuesday. In Tuesday trading, Atmos Energy Corp. shares are currently up about 0.3% on the day.