Looking at the universe of stocks we cover at Dividend Channel, on 5/16/13, Select Medical Holdings Corp ( SEM) will trade ex-dividend, for its quarterly dividend of $0.10, payable on 5/30/13. As a percentage of SEM's recent stock price of $8.05, this dividend works out to approximately 1.24%, so look for shares of Select Medical Holdings Corp to trade 1.24% lower — all else being equal — when SEM shares open for trading on 5/16/13.Below is a dividend history chart for SEM, showing historical dividends prior to the most recent $0.10 declared by Select Medical Holdings Corp: In general, dividends are not always predictable; but looking at the history above can help in judging whether the most recent dividend from SEM is likely to continue, and whether the current estimated yield of 4.97% on annualized basis is a reasonable expectation of annual yield going forward. The chart below shows the one year performance of SEM shares, versus its 200 day moving average: Looking at the chart above, SEM's low point in its 52 week range is $7.21 per share, with $14.89 as the 52 week high point — that compares with a last trade of $8.09. According to the ETF Finder at ETF Channel, SEM makes up 1.11% of the Dynamic Healthcare Sector Portfolio ETF ( PTH) which is trading up by about 0.7% on the day Tuesday. In Tuesday trading, Select Medical Holdings Corp shares are currently down about 0.4% on the day.