While "the trend is your friend" when it comes to short-term investing or trading, timing entries into the trend is a key determinant of success. And increasing the odds of success by making sure the sustainability of a trend isn't easy.Often, the direction of a stock's price movement reverses quickly after taking a position in it, making investors incur a short-term capital loss. So, it's important to ensure that there are enough factors -- such as sound fundamentals, positive earnings estimate revisions, ...