HKSI Paper 12 - independent subject foundations study materials
HKSI Paper 12 - independent subject foundations study resources

HKSI Paper 12 - independent subject foundations practice questions

One question at a time. Build your HKSI Paper 12 - independent subject foundations understanding.

First 50 of 190 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Investment instruments, portfolios and measured performance

Which feature most clearly distinguishes a unit trust from a mutual fund corporation?

  1. A unit trust is constituted by a trust deed while a mutual fund corporation is a company with shareholders Correct answer.
  2. A unit trust cannot invest in equities
  3. A mutual fund corporation has no manager
  4. A unit trust must always be closed-ended

Explanation

A unit trust is created under a trust deed, with a trustee and manager and investors holding units. A mutual fund corporation (open-ended investment company) is a body corporate in which investors hold shares. The economic exposure can be similar, but the legal form differs.

Question 2Investment instruments, portfolios and measured performance

What is the defining feature of an open-end fund?

  1. Its units trade on an exchange at a price set by supply and demand
  2. It continuously issues and redeems units at net asset value Correct answer.
  3. It has a fixed number of units that never changes
  4. It can only be sold to professional investors

Explanation

An open-end fund stands ready to issue new units to incoming investors and redeem units from departing investors, normally at or close to net asset value (NAV) per unit. The fund's size therefore expands and contracts with investor flows.

Question 3Investment instruments, portfolios and measured performance

A closed-end fund's units are quoted at a price 8% below their net asset value. This situation is described as the fund trading at:

  1. A premium
  2. A discount Correct answer.
  3. Par
  4. A spread

Explanation

When a closed-end fund's market price is below its net asset value (NAV) per unit, it is said to trade at a discount to NAV. If the price were above NAV it would trade at a premium. Closed-end discounts arise because units trade on supply and demand rather than being redeemed at NAV.

Question 4Investment instruments, portfolios and measured performance

How is the net asset value (NAV) per unit of an open-end fund normally calculated?

  1. Total assets divided by the number of units in issue
  2. (Total assets minus total liabilities) divided by the number of units in issue Correct answer.
  3. Total liabilities divided by the number of units in issue
  4. The latest traded price of the unit on an exchange

Explanation

NAV per unit equals the fund's net assets (total assets minus total liabilities, including accrued fees) divided by the number of units in issue. It represents each unit's share of the fund's net worth and is the basis for subscriptions and redemptions in an open-end fund.

Question 5Investment instruments, portfolios and measured performance

An investor pays a 5% sales charge when buying units, deducted from the amount invested. This charge is best described as a:

  1. Front-end load Correct answer.
  2. Back-end load
  3. Management fee
  4. Performance fee

Explanation

A front-end load (initial sales charge) is taken from the investor's money at the time of purchase, so only the balance is invested in units. A back-end load is charged on redemption, while management and performance fees are ongoing charges on the fund's assets.

Question 6Investment instruments, portfolios and measured performance

A fund charges a fee of 20% of returns above a stated hurdle rate. What is this fee called?

  1. Management fee
  2. Performance fee Correct answer.
  3. Redemption fee
  4. Trustee fee

Explanation

A performance fee rewards the manager with a share (here 20%) of returns generated above a hurdle rate or benchmark. It is common in hedge funds and is often subject to a high-water mark so the manager is not paid twice for recovering prior losses.

Question 7Investment instruments, portfolios and measured performance

Which document gives prospective retail investors the key information they need to make an informed decision about an authorised fund, including objectives, risks and charges?

  1. The annual report only
  2. The offering document (prospectus) Correct answer.
  3. The trust deed only
  4. The custodian agreement

Explanation

The offering document, or prospectus, is the principal disclosure document for investors. It sets out the fund's investment objective and policy, risk factors, fees and charges, dealing arrangements and key parties, enabling an informed investment decision.

Question 8Investment instruments, portfolios and measured performance

Under Hong Kong's Mandatory Provident Fund (MPF) system, what must an MPF scheme normally offer members as a low-risk default-type option?

  1. A leveraged equity fund
  2. A guaranteed fund or conservative fund Correct answer.
  3. A single-stock fund
  4. A commodity futures fund

Explanation

MPF schemes provide a range of constituent funds, and members must have access to lower-risk options such as an MPF Conservative Fund or a guaranteed fund. The Default Investment Strategy also provides a standardised, lower-cost option for members who do not actively choose.

Question 9Investment instruments, portfolios and measured performance

The Stock Connect programmes between Hong Kong and the Mainland exchanges primarily allow investors to:

  1. Trade currencies on margin
  2. Trade eligible shares listed on the linked exchange across the border Correct answer.
  3. Buy physical gold
  4. Trade only Hong Kong government bonds

Explanation

Stock Connect (Shanghai-Hong Kong and Shenzhen-Hong Kong) lets Hong Kong and overseas investors trade eligible Mainland-listed shares (northbound) and Mainland investors trade eligible Hong Kong-listed shares (southbound), within daily quotas, through their local brokers and clearing systems.

Question 10Investment instruments, portfolios and measured performance

The Qualified Domestic Institutional Investor (QDII) scheme is designed to allow:

  1. Overseas investors to buy Mainland A-shares
  2. Approved Mainland institutions to invest in overseas securities within a quota Correct answer.
  3. Hong Kong retail investors to buy property in the Mainland
  4. Foreign banks to issue Renminbi bonds in Hong Kong

Explanation

QDII permits approved Mainland Chinese institutions to invest in offshore (overseas) securities markets, subject to an allocated quota. It is an outbound channel, complementing inbound schemes such as QFI that bring foreign money into Mainland markets.

Question 11Investment instruments, portfolios and measured performance

The Cross-boundary Wealth Management Connect scheme is mainly intended to let:

  1. Greater Bay Area residents invest in eligible wealth-management products across the boundary Correct answer.
  2. Global hedge funds short-sell Mainland shares
  3. Companies list simultaneously in Hong Kong and London
  4. Banks set commercial lending rates

Explanation

Wealth Management Connect allows eligible residents in the Guangdong-Hong Kong-Macao Greater Bay Area to invest in eligible wealth-management and fund products distributed across the boundary, through participating banks and within investment quotas, broadening cross-border retail access.

Question 12Investment instruments, portfolios and measured performance

Which of the following is a key reason institutional and retail investors use managed (collective investment) funds rather than buying securities individually?

  1. Funds guarantee a positive return each year
  2. Funds provide professional management and instant diversification Correct answer.
  3. Funds remove all fees
  4. Funds are exempt from market risk

Explanation

Collective investment schemes pool many investors' money, giving access to professional management, diversification across many securities, economies of scale and administrative convenience that small individual investors could not easily achieve on their own.

Question 13Investment instruments, portfolios and measured performance

An exchange-traded fund (ETF) that holds the constituents of an index in their index weights is best described as using which approach?

  1. Active stock selection
  2. Physical (full) replication Correct answer.
  3. Leveraged trading
  4. Discretionary market timing

Explanation

A physically replicating ETF buys and holds the actual index constituents in their respective weights so its performance closely tracks the index. This is a passive approach; the alternative is synthetic replication using derivatives such as swaps.

Question 14Investment instruments, portfolios and measured performance

Compared with an unlisted open-end fund, a key advantage of an exchange-traded fund (ETF) for many investors is that it:

  1. Can be bought and sold throughout the trading day at market prices Correct answer.
  2. Always trades at a large premium to NAV
  3. Has no management fee
  4. Cannot be redeemed at all

Explanation

An ETF lists on an exchange, so investors can trade it intraday at prevailing market prices like a share, rather than only at the once-a-day dealing NAV of a traditional open-end fund. An arbitrage/creation-redemption mechanism keeps the price close to NAV.

Question 15Investment instruments, portfolios and measured performance

Which of the following is a typical characteristic of a hedge fund relative to a traditional long-only equity fund?

  1. It is restricted to investing only in government bonds
  2. It may use leverage, short selling and derivatives and often charges a performance fee Correct answer.
  3. It must publish a daily NAV to the public
  4. It is prohibited from using any derivatives

Explanation

Hedge funds pursue absolute-return strategies and can use leverage, short selling and derivatives, and they commonly charge both a management fee and a performance fee. They are usually offered to professional or qualified investors with fewer constraints than authorised retail funds.

Question 16Investment instruments, portfolios and measured performance

A money market fund primarily invests in:

  1. Long-dated equities
  2. Short-term, high-quality debt instruments such as Treasury bills and certificates of deposit Correct answer.
  3. Physical real estate
  4. Distressed corporate bonds

Explanation

Money market funds hold short-term, high-credit-quality instruments such as Treasury bills, certificates of deposit and commercial paper. They aim for capital preservation and liquidity with modest income, making them low-risk relative to equity or long-bond funds.

Question 17Investment instruments, portfolios and measured performance

The Mainland-Hong Kong Mutual Recognition of Funds (MRF) arrangement allows eligible funds to:

  1. Be sold to retail investors across the boundary after the host regulator's recognition Correct answer.
  2. Avoid all regulation in both markets
  3. Be sold only to the manager's employees
  4. Convert automatically into ETFs

Explanation

Under MRF, eligible Mainland and Hong Kong public funds can be offered to retail investors in the other market once recognised by the host regulator, subject to eligibility conditions. It expands cross-boundary distribution while keeping investor-protection requirements.

Question 18Investment instruments, portfolios and measured performance

Which party is responsible for the safekeeping of an authorised fund's assets and for overseeing that the manager acts in accordance with the fund's constitutive documents?

  1. The distributor
  2. The trustee or custodian Correct answer.
  3. The auditor
  4. The transfer agent only

Explanation

The trustee (for a unit trust) or custodian (for a corporate fund) holds the assets in safekeeping, segregated from the manager, and provides independent oversight that the manager complies with the trust deed or articles. This separation protects investors.

Question 19Investment instruments, portfolios and measured performance

A fund of funds is a vehicle that:

  1. Invests primarily in other collective investment schemes rather than directly in securities Correct answer.
  2. Invests only in a single stock
  3. Is prohibited from charging any fees
  4. Must always be closed-ended

Explanation

A fund of funds invests mainly in units or shares of other underlying funds, offering an extra layer of diversification and manager selection. Investors should note it can involve two layers of fees: those of the fund of funds and those of the underlying funds.

Question 20Investment instruments, portfolios and measured performance

Which statement about index (passive) funds is correct?

  1. They aim to outperform a benchmark through active stock picking
  2. They aim to match the return of a benchmark index, usually at low cost Correct answer.
  3. They guarantee they will beat the market
  4. They never hold any of the index constituents

Explanation

An index fund is a passive vehicle whose objective is to replicate the performance of a chosen benchmark index, before fees, typically with low management costs and low turnover. It does not try to beat the index through active selection.

Question 21Investment instruments, portfolios and measured performance

A guaranteed fund typically promises that, provided the investor holds for a specified period, the investor will receive:

  1. At least a stated minimum amount, often the original capital Correct answer.
  2. Double the original investment
  3. The highest return of any fund that year
  4. A fixed 10% return per month

Explanation

A guaranteed fund offers a guarantee (often of the original capital, sometimes plus a minimum return) if the investor stays until the guarantee date. The guarantee usually depends on the strength of the guarantor and on holding for the full term.

Question 22Investment instruments, portfolios and measured performance

An investment returns 10%, 20% and minus 5% over three years. Its arithmetic mean annual return is:

  1. 8.33% Correct answer.
  2. 10%
  3. 25%
  4. 5%

Explanation

The arithmetic mean is the simple average: (10% + 20% + (-5%)) / 3 = 25% / 3 = 8.33%. The arithmetic mean is useful for estimating expected single-period returns but overstates compounded growth over multiple periods.

Question 23Investment instruments, portfolios and measured performance

For a series of multi-period returns, the geometric mean return is generally:

  1. Higher than the arithmetic mean
  2. Equal to the arithmetic mean only when returns vary
  3. Lower than or equal to the arithmetic mean Correct answer.
  4. Always negative

Explanation

The geometric mean accounts for compounding and is always less than or equal to the arithmetic mean; they are equal only when every period's return is identical. The geometric mean better represents the actual compound growth rate of an investment over time.

Question 24Investment instruments, portfolios and measured performance

An asset has a 60% chance of returning 10% and a 40% chance of returning minus 5%. Its expected return is:

  1. 2.5%
  2. 4% Correct answer.
  3. 6%
  4. 7.5%

Explanation

Expected return is the probability-weighted average of outcomes: (0.60 x 10%) + (0.40 x -5%) = 6% + (-2%) = 4%. This weighting reflects how likely each outcome is.

Question 25Investment instruments, portfolios and measured performance

In portfolio theory, the standard deviation of returns is used as a measure of:

  1. Expected return
  2. Total risk (variability of returns) Correct answer.
  3. The risk-free rate
  4. Liquidity

Explanation

Standard deviation measures the dispersion of returns around their mean, and is the standard proxy for total risk (variability). A higher standard deviation means returns are more spread out and the investment is considered more risky.

Question 26Investment instruments, portfolios and measured performance

Assuming returns are normally distributed with a mean of 8% and a standard deviation of 10%, approximately 68% of outcomes fall within which range?

  1. Minus 12% to 28%
  2. Minus 2% to 18% Correct answer.
  3. 0% to 8%
  4. 8% to 18% only

Explanation

For a normal distribution, about 68% of outcomes lie within one standard deviation of the mean. Here that is 8% plus or minus 10%, i.e. from -2% to 18%. About 95% lie within two standard deviations (-12% to 28%).

Question 27Investment instruments, portfolios and measured performance

Two assets have a correlation coefficient of plus 1.0. Combining them in a portfolio will:

  1. Eliminate all risk
  2. Provide no risk-reduction benefit from diversification Correct answer.
  3. Always reduce risk to zero
  4. Increase expected return automatically

Explanation

A correlation of +1 means the two assets move perfectly together, so combining them gives no diversification benefit; portfolio risk is simply the weighted average of the individual risks. Diversification benefits arise only when correlation is below +1.

Question 28Investment instruments, portfolios and measured performance

The greatest diversification benefit (largest reduction in portfolio risk) is achieved when two assets have a correlation coefficient that is:

  1. Equal to plus 1.0
  2. Equal to zero
  3. As close as possible to minus 1.0 Correct answer.
  4. Greater than plus 1.0

Explanation

The lower (more negative) the correlation between two assets, the greater the diversification benefit. A correlation of -1 (perfect negative correlation) offers the maximum risk reduction, in theory allowing risk to be eliminated with the right weights.

Question 29Investment instruments, portfolios and measured performance

The 'efficient frontier' in modern portfolio theory represents:

  1. All possible portfolios regardless of risk
  2. Portfolios offering the highest expected return for each level of risk Correct answer.
  3. Only risk-free portfolios
  4. Portfolios that are guaranteed to make money

Explanation

The efficient frontier is the set of portfolios that maximise expected return for each level of risk (or equivalently minimise risk for each level of return). Rational, risk-averse investors choose portfolios on this frontier; portfolios below it are inefficient.

Question 30Investment instruments, portfolios and measured performance

An investor's indifference curves in risk-return space slope upward because:

  1. Investors prefer more risk for its own sake
  2. A risk-averse investor requires higher expected return to accept higher risk Correct answer.
  3. Risk has no effect on satisfaction
  4. Returns fall as risk rises

Explanation

For a risk-averse investor, each indifference curve shows combinations of risk and return giving equal satisfaction. They slope upward because the investor must be compensated with higher expected return to be willing to take on more risk. Steeper curves indicate greater risk aversion.

Question 31Investment instruments, portfolios and measured performance

In the Capital Asset Pricing Model (CAPM), beta measures an asset's:

  1. Total risk
  2. Sensitivity to movements in the overall market (systematic risk) Correct answer.
  3. Liquidity
  4. Dividend yield

Explanation

Beta measures the sensitivity of an asset's returns to movements in the overall market, i.e. its systematic (non-diversifiable) risk. A beta of 1 moves with the market; above 1 is more volatile than the market; below 1 is less volatile.

Question 32Investment instruments, portfolios and measured performance

Using the CAPM, if the risk-free rate is 3%, the expected market return is 9% and a stock's beta is 1.5, the stock's required return is:

  1. 9%
  2. 12% Correct answer.
  3. 13.5%
  4. 10.5%

Explanation

CAPM required return = risk-free rate + beta x (market return - risk-free rate) = 3% + 1.5 x (9% - 3%) = 3% + 1.5 x 6% = 3% + 9% = 12%. The market risk premium here is 6%, amplified by the beta of 1.5.

Question 33Investment instruments, portfolios and measured performance

According to the CAPM, which type of risk is the investor rewarded for bearing?

  1. Unsystematic (specific) risk
  2. Systematic (market) risk Correct answer.
  3. Inflation risk only
  4. No risk is rewarded

Explanation

The CAPM holds that only systematic (market) risk, measured by beta, is rewarded with a higher expected return, because unsystematic risk can be diversified away. Investors should not expect compensation for taking diversifiable specific risk.

Question 34Investment instruments, portfolios and measured performance

A stock with a beta of 0.7 would generally be expected to:

  1. Be more volatile than the market
  2. Be less volatile than the market Correct answer.
  3. Have no relationship with the market
  4. Always lose money

Explanation

A beta below 1 indicates the stock tends to move less than the market. With a beta of 0.7, if the market rises or falls 10%, the stock would be expected to move about 7% in the same direction, making it less volatile than the market (a defensive characteristic).

Question 35Investment instruments, portfolios and measured performance

The security market line (SML) plots expected return against:

  1. Standard deviation
  2. Beta Correct answer.
  3. Time
  4. Dividend yield

Explanation

The security market line, derived from the CAPM, plots an asset's expected (required) return against its beta. Correctly priced assets lie on the SML; an asset plotting above it would be considered underpriced (offering more return than required for its beta).

Question 36Investment instruments, portfolios and measured performance

Arbitrage Pricing Theory (APT) differs from the CAPM mainly because APT:

  1. Uses only the market portfolio as the single risk factor
  2. Allows returns to depend on multiple systematic risk factors Correct answer.
  3. Ignores risk entirely
  4. Applies only to bonds

Explanation

Arbitrage Pricing Theory is a multi-factor model: an asset's expected return depends on its sensitivities to several systematic risk factors (such as inflation, interest rates or industrial production), not just one market factor as in the single-factor CAPM.

Question 37Investment instruments, portfolios and measured performance

Total risk of a single asset can be decomposed into:

  1. Systematic risk plus unsystematic risk Correct answer.
  2. Liquidity risk plus tax risk
  3. Only systematic risk
  4. Only unsystematic risk

Explanation

An asset's total risk comprises systematic (market) risk, which cannot be diversified away, and unsystematic (specific) risk, which can be reduced through diversification. In a well-diversified portfolio, specific risk is largely eliminated, leaving mainly systematic risk.

Question 38Investment instruments, portfolios and measured performance

As more uncorrelated securities are added to a portfolio, the portfolio's unsystematic risk typically:

  1. Increases without limit
  2. Decreases and approaches a minimum Correct answer.
  3. Stays exactly the same
  4. Becomes negative

Explanation

Adding more securities with low correlations reduces unsystematic (specific) risk, with the benefit diminishing as the number grows. Beyond a certain point, most diversifiable risk is removed and the remaining risk is essentially systematic (market) risk.

Question 39Investment instruments, portfolios and measured performance

The covariance between the returns of two assets measures:

  1. Their average return
  2. The degree to which their returns move together Correct answer.
  3. Their combined liquidity
  4. The risk-free rate

Explanation

Covariance measures how two assets' returns move in relation to each other. A positive covariance means they tend to move in the same direction; a negative covariance means opposite directions. Dividing covariance by the product of the two standard deviations gives the correlation coefficient.

Question 40Investment instruments, portfolios and measured performance

A portfolio is split 50% in Asset A (expected return 8%) and 50% in Asset B (expected return 12%). The portfolio's expected return is:

  1. 8%
  2. 10% Correct answer.
  3. 12%
  4. 20%

Explanation

The expected return of a portfolio is the weighted average of its components' expected returns: (0.5 x 8%) + (0.5 x 12%) = 4% + 6% = 10%. Note that, unlike return, portfolio risk is not simply the weighted average because correlation matters.

Question 41Investment instruments, portfolios and measured performance

Which statement about a portfolio's standard deviation is correct?

  1. It always equals the weighted average of the assets' standard deviations
  2. It is usually less than the weighted average of the assets' standard deviations when correlation is below plus 1 Correct answer.
  3. It is always zero
  4. It is unaffected by correlation between assets

Explanation

Because of diversification, a portfolio's standard deviation is generally lower than the weighted average of the individual standard deviations whenever the assets are not perfectly positively correlated. Only at a correlation of +1 does it equal the weighted average.

Question 42Investment instruments, portfolios and measured performance

The 'market risk premium' is defined as:

  1. The risk-free rate
  2. The expected return on the market portfolio minus the risk-free rate Correct answer.
  3. A stock's dividend yield
  4. The inflation rate

Explanation

The market risk premium is the additional return investors expect for holding the risky market portfolio rather than the risk-free asset: expected market return minus the risk-free rate. In the CAPM it is multiplied by beta to give an asset's risk premium.

Question 43Investment instruments, portfolios and measured performance

An assumption underlying the simple use of standard deviation and the normal distribution to describe returns is that:

  1. Returns can only be positive
  2. Returns are symmetrically distributed around the mean Correct answer.
  3. Risk does not exist
  4. All investors are risk-seeking

Explanation

Using the normal distribution assumes returns are symmetric around the mean, so the probabilities above and below the mean mirror each other. In reality return distributions can be skewed and have fat tails, which is a limitation of this simplifying assumption.

Question 44Investment instruments, portfolios and measured performance

If two assets have a correlation of zero, combining them in a portfolio will:

  1. Provide no diversification benefit
  2. Provide some diversification benefit, reducing portfolio risk below the weighted average Correct answer.
  3. Increase portfolio risk above the weighted average
  4. Eliminate all risk

Explanation

A correlation of zero means the assets' returns are uncorrelated, which still provides meaningful diversification: portfolio risk falls below the simple weighted average of the individual risks, though not to zero. Greater benefit requires negative correlation.

Question 45Investment instruments, portfolios and measured performance

The arithmetic mean tends to overstate the actual multi-period growth of an investment because it:

  1. Accounts for compounding
  2. Ignores the effect of compounding and the impact of volatility on terminal wealth Correct answer.
  3. Uses only negative returns
  4. Is always smaller than the geometric mean

Explanation

The arithmetic mean simply averages periodic returns and does not capture compounding. Because losses require larger subsequent gains to recover, volatility reduces compound growth, so the geometric mean (which captures this) is the better measure of realised multi-period growth.

Question 46Investment instruments, portfolios and measured performance

An active investment management strategy is one that:

  1. Seeks to replicate a benchmark index
  2. Seeks to outperform a benchmark through security selection or market timing Correct answer.
  3. Holds only cash
  4. Never trades

Explanation

Active management attempts to beat a benchmark by selecting securities, timing markets or rotating sectors, based on the manager's research and views. It usually involves higher turnover and higher fees than passive management, which simply tracks an index.

Question 47Investment instruments, portfolios and measured performance

A passive management strategy is generally favoured by investors who believe that markets are:

  1. Highly inefficient and easy to beat
  2. Reasonably efficient, making consistent outperformance after costs difficult Correct answer.
  3. About to crash
  4. Closed to retail investors

Explanation

Passive investing rests on the view that markets are sufficiently efficient that consistently beating a benchmark after fees and costs is difficult. Investors therefore seek low-cost market exposure through index funds or ETFs rather than paying for active management.

Question 48Investment instruments, portfolios and measured performance

A value-investing style focuses on buying stocks that are:

  1. Trading at high price-earnings multiples with rapid growth
  2. Considered undervalued relative to fundamentals such as earnings or book value Correct answer.
  3. Only newly listed
  4. Only in the technology sector

Explanation

Value investors look for stocks that appear cheap relative to fundamentals such as earnings, book value or cash flow, expecting the market to eventually recognise their true worth. They often favour low P/E and low price-to-book ratios.

Question 49Investment instruments, portfolios and measured performance

A growth-investing style typically targets companies with:

  1. Low growth and high dividends
  2. Above-average earnings growth prospects, often with higher valuations Correct answer.
  3. Falling revenues
  4. Only government ownership

Explanation

Growth investors seek companies expected to grow earnings or revenues faster than average, and are often willing to pay higher valuation multiples for that growth potential. Such stocks may pay little or no dividend, reinvesting profits to fund expansion.

Question 50Investment instruments, portfolios and measured performance

The Sharpe ratio measures:

  1. Return per unit of systematic risk (beta)
  2. Excess return (over the risk-free rate) per unit of total risk (standard deviation) Correct answer.
  3. Tracking error
  4. The dividend yield

Explanation

The Sharpe ratio equals (portfolio return minus risk-free rate) divided by the portfolio's standard deviation. It shows how much excess return is earned per unit of total risk, allowing risk-adjusted comparison of portfolios. A higher Sharpe ratio is better.