Since the stock market value is on 75% does that mean it is under valued? To be honest, I too am trying to figure out the relationship between the two. The stock market is valuing the companies that produced the goods measure by gnp. For a company can produce $100 in goods and service today. However, the company can itself be worth many times $100 dollar since it’s value is a combination of what it produce today and what it can produce tomorrow.Anyway, I don’t know what is a good mathematical model to relate gdp and market value.