Securities are evaluated based on their potential for growth. In other words, a security has a market value and investors try and estimate what the value will be in the future to make a buy/sell decision. An analysis that compares the actual value of the security to the market value is called fundamental analysis.
For example, you can compare whether a stock is fairly valued by comparinng the its P/E (Price per share/Earnings per share) ratio with comparable stocks.
In addition, you can compare bonds based on the yield to maturity (annualized rate of return) and duration (sensitivity to interest rates)