Investing.com - Investors need to be more positive.That's the message from Credit Suisse (SIX:CSGN).In a note to clients, the Wall Street firm said investors are "under-estimating the market's potential upside and over-estimating the risks."Credit Suisse said there are numerous positives for stocks, including the best corporate earnings in years, a strong economy and even more attractive valuations, following the market's 10 correction. The firm is forecasting 2.8 GDP growth in 2018 and a 3,000 year-end, price level for the S&P 500.