You can evaluate long-term value by doing your due diligence by researching the company's strategy and financials. You can tell if a stock is undervalued by cal

You can evaluate long-term value by doing your due diligence by researching the company's strategy and financials. You can tell if a stock is undervalued by calculating its price to earnings ratio. Day trading is gambling. Valuation and long-term forecast is irrelevant to a day trader. Stocks constantly fluctuate and gains on one time scale can be losses on another. This is just one reason a seller of an undervalued stock is not necessarily stupid.