The paper is devoted to our research on the effectiveness of using different middle- and long-term trading strategies based on computer analysis (CA) indicators. This paper contains a brief overview of three technical analysis indicators that are usually used for getting buy or sell signals for some specific financial instruments (FIs). We have described the approach that allows using such signals not only for a single FI but for a whole investment portfolio. The initial investment portfolio is generated using Markowitz’s Modern Portfolio Theory. The paper contains an overview of similar approaches presented by other researchers. During the experimental part of the research, we compared the effectiveness of using such CA indicators as moving average (MA), relative strength index (RSI), and support and resistance (S&R). The results prove that using certain CA strategies allows not only to increase the initial investment portfolio profitability on rising periods in the financial market but also may reduce loss during a global financial market recession.