As the investment is likely to bolster the semiconductor industry in Japan and strengthen ties between major Japanese and Taiwanese companies, it could have a positive effect on the Japanese stock market. EWJ, tracking such stocks, may see benefits from improved investor sentiment towards Japanese equities.

Toyota's investment in TSMC's plant is directly aimed at securing a more reliable semiconductor supply chain, which is critical for modern vehicle production. This move is likely to be viewed positively by investors as it addresses a significant bottleneck in production, potentially leading to improved efficiency and reduced costs in the long term.

The investment from Toyota not only provides TSMC with financial resources but also strengthens its relationship with a major player in the automotive industry. This could lead to increased demand for TSMC's semiconductors in the automotive sector, potentially boosting its revenue and market position.