The book was not about the stock market. Rather, it was about the distinction between flows, income and stocks, meaning debt, capital, and so on.
But to answer the question you put just before this, on trying to get firms to invest for the future, I would say that firms need to believe that there will be aggregate demand, that there is a demand for their products. If that demand is not forthcoming from consumers any more, then, as I said at the beginning in my presentation, it has to come from the government, because it's not going to come from our exports to Europe or to the United States next year.