Roy's Safety-First Criterion - SFRatio

Definition of 'Roy's Safety-First Criterion - SFRatio'


An approach to investment decisions that sets a minimum required return for a given level of risk. The Roy's safety-first criterion allows portfolios to be compared based on the probability that their returns will fall below this minimum desired threshold. It is calculated by subtracting the minimum desired return from the expected return of the portfolio and dividing the result by the standard deviation of portfolio returns. The optimal portfolio will be the one that minimizes the probability that the portfolio's return will fall below a threshold level.

Also known as the "SFRatio".

Investopedia explains 'Roy's Safety-First Criterion - SFRatio'


The safety-first ratio is calculated as:
= E(r) - Threshold Return
Standard Deviation

The optimal decision is to choose the portfolio with the highest SFRatio. The SFRatio is very similar to the Sharpe ratio; for normally distributed returns, when the minimum return is equal to the risk free rate this will provide the same conclusions as if we were to pick the return with the maximum Sharpe ratio. The SFRatio is commonly found in financial courses and certificates, such as the CFA Level I material.



comments powered by Disqus
Hot Definitions
  1. Identity Fraud Reimbursement Program

    A financial product that offers reimbursment for the costs associated with having been a victim of identity theft. These costs may include getting affidavits notarized for police and financial institutions, postage for sending certified mail to police and financial institutions, lost earnings resulting from time spent recovering one's identity, and legal fees.
  2. Cash and Carry Transaction

    A type of transaction in the futures market in which the cash or spot price of a commodity is below the futures contract price. Cash and carry transactions are considered arbitrage transactions.
  3. Amplitude

    The difference in price from the midpoint of a trough to the midpoint of a peak of a security. Amplitude is positive when calculating a bullish retracement (when calculating from trough to peak) and negative when calculating a bearish retracement (when calculating from peak to trough).
  4. Ascending Triangle

    A bullish chart pattern used in technical analysis that is easily recognizable by the distinct shape created by two trendlines. In an ascending triangle, one trendline is drawn horizontally at a level that has historically prevented the price from heading higher, while the second trendline connects a series of increasing troughs.
  5. National Best Bid and Offer - NBBO

    A term applying to the SEC requirement that brokers must guarantee customers the best available ask price when they buy securities and the best available bid price when they sell securities.
  6. Maintenance Margin

    The minimum amount of equity that must be maintained in a margin account. In the context of the NYSE and FINRA, after an investor has bought securities on margin, the minimum required level of margin is 25% of the total market value of the securities in the margin account.
Trading Center