Most of us have heard the dictum "the trend is your friend." And this is undeniably the key to success when it comes to short-term investing or trading. But it isn't easy to ensure the sustainability of a trend and profit from it.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, etc. -- ...