In general, to invest is to allocate money (or sometimes another resource, such as time) in the expectation of some benefit in the future – for example, investment in durable goods, in real estate by the service industry, in factories for manufacturing, in product development, and in research and development. However, this article focuses specifically on investment in financial assets. In finance, the benefit from investment is called a return. The return may consist of capital gains or investment income, including dividends, interest, rental income etc., or a combination of the two. The projected economic return is the appropriately discounted value of the future returns. The historic return comprises the actual capital gain (or loss) or income (or both) over a period of time. Investors generally expect higher returns from riskier investments. Financial assets range from low-risk, low-return investments, such as high-grade government bonds, to those with higher risk and higher expected commensurate reward, such as emerging markets stock investments. Investors, particularly novices, are often advised to adopt a particular investment strategy and diversify their portfolio. Diversification has the statistical effect of reducing overall risk. Investment differs from arbitrage, in which profit is generated without investing capital or bearing risk. An investor may bear a risk of loss of some or all of their capital invested, whereas in saving (such as in a bank deposit) the risk of loss in nominal value is normally remote. (Note that if the currency of a savings account differs from the account holder's home currency, then there is the risk that the exchange rate between the two currencies will move unfavorably, so that the value in the account holder's home currency of the savings account decreases.) Speculation involves a level of risk which is greater than most investors would generally consider justified by the expected return. An alternative characterization of speculation is its short-term, opportunistic nature.