......Why would you assume that?
If price has risen to gain a position above the 50EMA, it might be in a trend. I don't say it is, this is just a crude dividing line. Prices blow the 50EMA are probably not in on-going uptrends, prices above the 50EMA might be in on-going uptrends. They won't all be, but some might be. Trend theory says that the most likely thing a price in a rising trend will soon be doing is rising.