The Tokyo Price Index (TOPIX) is a Japanese stock market index that serves as a benchmark for the Tokyo Stock Exchange (TSE). It is composed of all domestic companies traded in the TSE’s first section, which represents Japan's largest firms by market capitalization. Companies in this section are blue chips, meaning that they are mature, well-established businesses that, despite their large size, experience solid and continuing growth.

TOPIX weights the performance of these companies according to their market value, rather than their share price. This method provides greater accuracy than the more commonly-used price-weighted indexing method. Additionally, this weighting method is more representative of how the overall market is performing.

TOPIX is one of several stock indices that investors use to gauge the performance of the Japanese market as a whole. In comparison to the Nikkei 225, which is comprised of the top 225 blue-chip companies traded on the TSE, TOPIX is a more dynamic index. This difference arises from the fact that TOPIX includes all domestic companies by market capitalization, as opposed to only the top 225 blue chips. As such, investors can analyse and track the performance of the Japanese stock market more accurately and efficiently with TOPIX.

Due to TOPIX’s popularity, investors can purchase exchange traded funds (ETFs) such as the TOPIX Core 30 ETF that replicate the component stocks and weightings in TOPIX. This encourages greater diversity and allows investors to spread market risk more efficiently.

Overall, the Tokyo Price Index (TOPIX) is a comprehensive benchmark that accurately reflects the performance of the Tokyo Stock Exchange, allowing investors to track and monitor the performance of the entire Japanese stock market more effectively.