Investing in the stock market is secondary to the actual investment into activities performed by the companies that constitute it. Thus, investments decisions

Investing in the stock market is secondary to the actual investment into activities performed by the companies that constitute it. Thus, investments decisions made within such companies are those that promote their growth (or not). In this manner, without insider knowledge into the internal decisions those companies make, and thus the ability to judge the viability of their investments, investing in something other than a stock index is much riskier. But the stock market itself can still grow. The distinction is that investing in "the market" is an arms length investment that occurs well after the good or bad investments that affect the profitability of individual companies have occurred.