The global market portfolio refers to a theoretical investment strategy that involves holding a diversified mix of assets from all over the world. This type of portfolio is designed to maximize returns while minimizing risk by spreading investments across different countries, industries and asset classes such as stocks, bonds, commodities, etc. The idea behind this approach is that it allows an investor to benefit from growth opportunities in various regions without being too heavily exposed to the volatility of any one market or sector. In essence, a global market portfolio represents a well-diversified and balanced mix of assets that can provide stable long-term returns while reducing risk.