Japan Exchange Group (JPX) is considering a proposal to exclude companies with over 50% of their assets in cryptocurrencies from the Tokyo Stock Price Index (TOPIX). This move could affect Metaplanet and other digital asset treasuries (DATs), potentially blocking Metaplanet's scheduled listing on TOPIX after the October 2026 reconstitution. JPX has sought feedback from stakeholders on this proposal, which aims to protect investors from market volatility linked to crypto assets. Metaplanet, which was upgraded from small-cap to mid-cap in October 2025, has already been listed on the FTSE Japan Index and the FTSE All-World Index. However, exclusion from TOPIX could lead to passive outflows and affect domestic investors who use the index as a benchmark. The JPX's proposal follows a similar move by MSCI, which led to significant sell-offs in other crypto-heavy firms. Metaplanet's stock, listed on the Tokyo Stock Exchange, closed at $1.87, down 86% from its 2025 highs.