Bullish investors hope they can ride the momentum to big portfolio gains.It's been an encouraging year for investors. As of Aug. 13, the S&P 500 has climbed 14% and is trading just 4% off its peak price. The market might still believe that a recession can be avoided.However, some businesses have benefited more than others from the bullish tone. Fast-casual salad purveyor Sweetgreen (SG 1.63%) is in a league of its own. Its shares have skyrocketed 205% this year, a gain that would've tripled your money in le ...