The stock price prediction or forecasting is one of the important information in the stock market. Investors need stock price information before buying shares, while shareholders need stock price information for selling shares. There are many stock price prediction techniques have been proposed in the time series analysis. One of the simplest and powerful techniques is singular spectrum analysis, which works on the time series decomposition that is constructed using sub-series or window of the initial time series. However, choosing the exact window length is not easy because it depends on the time series characteristics. In this paper, the Hadamard transform of time series is proposed as an alternative technique to choose the window length in time series embedding. Technically, the length of the window for time series embedding is determined directly based on the size of the Hadamard spectrum. The experimental results show that the proposed method not only facilitates the determination of window length in time series embedding but can also improve the performance of the standard singular spectrum analysis method. The error rates of the proposed and the baseline methods (the standard singular spectrum analysis and the standard singular spectrum analysis with minimum description length) are 0.0088, 0.0194, and 0.1441, respectively.