Global Positioning System (GPS) signals, though critical to numerous civilian and industrial applications, remain susceptible to spoofing due to their unencrypted nature. While many existing defenses focus on single-antenna spoofing, multi-antenna spoofing has been theorized as a significantly more potent threat. However, practical realizations of multi-antenna spoofing have been limited by the stringent requirement of nanosecond-level synchronization.

This article proposes return-on-equity (ROE) networks for portfolio optimization, which integrate the DuPont analysis and graph theory. Portfolio diversification is interpreted as follows: An intercluster relationship of the network structure diversifies business models, whereas an innercluster relationship variegates different industries. The proposed approach is applied to the Chinese stock market. It shows that, in terms of the annualized return, the ROE network optimized portfolio reached$13.20\%$compared with$6.02\%$of the Shanghai Stock Exchange (SSE) Composite Index. It also shows that portfolios with 100–200 stocks, which are composed of the top 10%–20% ROE stocks, reached the highest return-risk efficiency.