Since 2014, Alphabet (NASDAQ: GOOGL )(NASDAQ: GOOG ) has been a keeper in my portfolio. The stock has delivered excellent returns and has managed to outperform itself time and time again.I'm a passionate investor from the Netherlands with 12 years of stock market experience. My articles usually contain a good overview of important investment criteria. A stock for my portfolio is of interest to me if the company has the following characteristics:1. Companies that are growing in both revenue, earnings and fre ...