Do consumers also invest?
It is true that we tend to think of Investment as something firms and businesses do, while consumers practice savings or "invest" in utility-enhancing assets (like a house to live in). 

One could argue that when consumers buy shares of a corporation in the stock market they participate in productive investment, even though they do not control the decision-making process. 

But exactly because they do not affect the decision-making process it is better to think of such "investments" also as saving, and retain the word investment for the purposeful and decided-upon transformation of resources into productive use.