Investment has different meanings in finance and economics.
In economics, investment is the accumulation of newly produced physical entities, such as factories, machinery, houses, and goods inventories.
In finance, investment is putting money into an asset with the expectation of capital appreciation, dividends, and/or interest earnings. This may or may not be backed by research and analysis. Most or all forms of investment involve some form of risk, such as investment in equities, property, and even fixed interest securities which are subject, among other things, to inflation risk. It is indispensable for project investors to identify and manage the risks related to the investment.
In economics or macroeconomics
In economic theory or in macroeconomics, non-residential fixed investment is the amount purchased per unit time of goods which are not consumed but are to be used for future production (i.e. capital). Examples include railroad or factory construction. Investment in human capital includes costs of additional schooling or on-the-job training. Inventory investment is the accumulation of goods inventories; it can be positive or negative, and it can be intended or unintended. In measures of national income and output, "gross investment" ( represented by the variable I ) is a component of gross domestic product (GDP), given in the formula GDP = C + I + G + NX, where C is consumption, G is government spending, and NX is net exports, given by the difference between the exports and imports, X − M. Thus investment is everything that remains of total expenditure after consumption, government spending, and net exports are subtracted (i.e. I = GDP − C − G − NX).
Non-residential fixed investment (such as new factories) and residential investment (new houses) combine with inventory investment to make up I. "Net investment" deducts depreciation from gross investment. Net fixed investment is the value of the net increase in the capital stock per year.
Fixed investment, as expenditure over a period of time (e.g., "per year"), is not capital but rather leads to changes in the amount of capital. The time dimension of investment makes it a flow. By contrast, capital is a stock— that is, accumulated net investment to a point in time (such as December 31).
Investment is often modeled as a function of income and interest rates, given by the relation I = f(Y, r). An increase in income encourages higher investment, whereas a higher interest rate may discourage investment as it becomes more costly to borrow money. Even if a firm chooses to use its own funds in an investment, the interest rate represents an opportunity cost of investing those funds rather than lending out that amount of money for interest.
In finance, investment is the purchase of an asset or item with the hope that it will generate income or appreciate in the future and be sold at the higher price. It generally does not include deposits with a bank or similar institution. The term investment is usually used when referring to a long-term outlook. This is the opposite of trading or speculation, which are short-term practices involving a much higher degree of risk. Financial assets take many forms and can range from the ultra safe low return government bonds to much higher risk higher reward international stocks. A good investment strategy will diversify the portfolio according to the specified needs. The most famous and successful investor of all time is Warren Buffett. In March 2013 Forbes magazine had Warren Buffett ranked as number 2 in their Forbes 400 list. Buffett has advised in numerous articles and interviews that a good investment strategy is long term and choosing the right assets to invest in requires due diligence. Edward O. Thorp was a very successful hedge fund manager in the 1970s and 1980s that spoke of a similar approach. Another thing they both have in common is a similar approach to managing investment money. No matter how successful the fundamental pick is, without a proper money management strategy, full potential of the asset can’t be reached. Both investors have been shown to use principles from the Kelly criterion for money management. Numerous interactive calculators which use the kelly criterion can be found online.
In contrast, dollar (or pound etc.) cost averaging and market timing are phrases often used in marketing of collective investments and can be said to be associated with speculation.
Investments are often made indirectly through intermediaries, such as pension funds, banks, brokers, and insurance companies. These institutions may pool money received from a large number of individuals into funds such as investment trusts, unit trusts, SICAVs etc. to make large scale investments. Each individual investor then has an indirect or direct claim on the assets purchased, subject to charges levied by the intermediary, which may be large and varied. It generally, does not include deposits with a bank or similar institution. Investment usually involves diversification of assets in order to avoid unnecessary and unproductive risk.