Technical indicators are used by experts in stock trading. The purpose of this report is to investigate whether or not some indicators perform better when applied to stocks of specific market sectors. The investigation was conducted by implementing one algorithm for each of three different technical indicators, Relative Strength Index, Moving Average Convergence-Divergence, and Larry Williams %R. Each algorithm considered one trading strategy. Three market sectors defined by the GICS were included in the tests, Consumer Staples, Utilities, Information Technology. For each of these sectors at least one stock from each industry were tested. Results suggest that the performance of the Relative Strength Index indicator may be related to the sector of the stock to which it is applied, while %R showed no such indication, and MACD showed only a slight performance deviation between sectors. Further and more in-depth studies are required to confirm the results and conclusions drawn in this report.