Application of GARCH and mean-variance model in the U.S. financial market

How to obtain a high return and face the low-risk investment is hot topic widely discussed among investors. However, specific method of targeting optimal portfolio requires sophisticated mathematical computations. By research, some scholars found that theory helps investors get higher reduce risk. Thus, aim this paper collect optimize selected portfolio—Apple, Google, Netflix, Tesla, Walmart—by GARCH model Sharpe ratio, based on mean returns correlation matrix, which Google Apple are strongly positively correlated each other, while Walmart, Netflix weakly correlated. The price volatility equity shows stock will go down in next 7 days. We compare with NASDAQ composite find superiority our model.