Which of the following best describes investment risk?

Investment risk is fundamentally concerned with the possibility that an investment will not achieve the expected returns, which includes the chance of losing money. When individuals or institutions invest in assets, they are inherently taking on risk, which can stem from various factors such as market volatility, economic changes, and specific issues related to the investment itself. Therefore, saying that investment risk is the chance of losing money accurately encapsulates the core idea of risk involved in investing.

The other options examine different aspects of financial concepts but do not define investment risk. A guaranteed return on any asset reflects security rather than risk, which is the opposite of what is being defined. The inability to access funds at any time refers to liquidity risk, which is specific to the accessibility of invested funds rather than the potential loss associated with those investments. Lastly, the total amount invested pertains to investment size or capital invested, which does not contribute to the notion of risk involved in the potential for loss or gain from those investments. Thus, the definition provided in the correct answer captures the essence of investment risk comprehensively.