Do consumers also invest? Definition of Investment that I have found: 


Investment is the expenditure incurred on the procurement of such capital assets that would help in further production .


According to this, it means that investment is only made by producers. 

Am I correct in saying that only producers invest? Or 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.