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* * * ADMINISTRAÇÃO FINANCEIRA Aula 07 Risco e Retorno * * * Risco, Retorno e Mercado Financeiro Lições da história do mercado de capitais: Existe um prêmio por suportar risco; Quanto maior o retorno potencial, maior o risco; Isso é chamado de trade-off entre risco e retorno. Aula 07 – Risco e Retorno Calculando Riscos e Retornos * * * Retornos Totais Renda do investimento + ganhos de capital por mudança de preços Exemplo: Você comprou um bônus de $ 950 há um ano atrás. Você recebeu um cupom de $ 30 por semestre e pode vender o bônus por $ 975 hoje. Qual o ganho total e percentual? Renda = 30 + 30 = 60 Ganho de Capital = 975 – 950 = 25 Ganho Total = 60 + 25 = 85 Ganho Percentual = 85 / 950 = 0,0895 = 8,95% * * * Exemplo – Calculando Retornos Você comprou uma ação a $ 35,00 e recebeu $ 1,25 de dividendos. A ação vale hoje $ 40,00. Qual é seu retorno total em reais? R$ 1,25 + (40 – 35) = R$ 6,25 Qual seu retorno percentual? Dividendos = 1,25 / 35 = 3,57% Ganho de Capital = (40 – 35) / 35 = 14,29% Retorno percentual total = 3,57 + 14,29 = 17,86% * * * A Importância dos Mercados Financeiros Mercados financeiros permitem que companhias captem recursos para financiar sua atividade produtiva; Governo capte para financiar déficit e programas sociais; Indivíduos captem para aumentar sua renda e financiar consumo futuro; Os mercados financeiros também nos dão informações sobre os retornos que são exigidos pelos diversos níveis de risco assumido. * * * Retornos Médios * * * Prêmios de Risco Retorno extra (ganho) por tomar risco; Notas do Tesouro americano são consideradas livres de risco; O prêmio de risco é o retorno adicional sobre a taxa livre de risco. * * * Retornos Médios Anuais e Prêmios de Risco * * * Variância e Desvio-Padrão Variância e Desvio-Padrão medem o grau de volatilidade dos retornos de ativos; Quanto maior a volatilidade, maior o desvio-padrão e maior a incerteza; Variância histórica = soma do (retorno – retorno médio) ao quadrado / número de observações; Desvio-padrão = raiz quadrada da variância: DP = [ Σ (R – M)2 / n ] 1/2 * * * Exemplo – Variância x Desvio Padrão Ação 1 Variance = .0045 / (4-1) = .0015 Standard Deviation = .03873 (COEFICIENTE DE VARIAÇÃO) * * * Exemplo – Variância x Desvio Padrão Ação 2 Variance = .0045 / (4-1) = .0015 Standard Deviation = .03873 (COEFICIENTE DE VARIAÇÃO) * * * Conclusões Ação 2 tem um retorno médio maior que ação 1; Ação 2 também tem um desvio-padrão maior, ou seja, tem um risco maior; Quanto maior o risco, maior tende a ser o retorno; Contudo, importante é comparar o risco relativo ou relação risco / retorno; Ação 2 rende mais e tem uma menor relação risco / retorno (também conhecida como coeficiente de variação) -> melhor investimento * * * Distribuição Normal Distribuição em forma de sino e simétrica; 68% da distribuição –> concentra-se entre -1 e +1 desvio-padrão da média; 95% da distribuição –> concentra-se entre -2 e +2 desvios-padrão da média; 99% da distribuição –> concentra-se entre -3 e +3 desvios-padrão da média. * * * Distribuição Normal * * * Frequencia de Distribuição de Retornos * * * Média Geométrica x Aritmética Média aritmética – média simples dos retornos; Média geométrica – média composta dos retornos; A média geométrica será sempre menor que a aritmética, a menos que os retornos sejam iguais. Qual é melhor? Média aritmética é otimista para horizontes longos; Média geométrica é pessimista para horizontes curtos; Então a resposta depende do período analisado: 15 – 20 anos ou menos – use aritmética; 20 – 40 anos – faça um mix das duas; 40 anos ou mais: use geométrica. * * * Example: Computing Averages What is the arithmetic and geometric average for the following returns? Year 1 5% Year 2 -3% Year 3 12% Arithmetic average = (5 + (–3) + 12) / 3 = 4.67% Geometric average = [(1+0.05)*(1-0.03)*(1+0.12)]1/3 – 1 = 0.0449 = 4.49% * * * Efficient Capital Markets Stock prices are in equilibrium or are “fairly” priced If this is true, then you should not be able to earn “abnormal” or “excess” returns Efficient markets DO NOT imply that investors cannot earn a positive return in the stock market * * * Mercados Eficientes * * * What Makes Markets Efficient? There are many investors out there doing research As new information comes to market, this information is analyzed and trades are made based on this information Therefore, prices should reflect all available public information If investors stop researching stocks, then the market will not be efficient * * * Concepções Erradas Comuns na Hipótese de Mercados Eficientes Efficient markets do not mean that you can’t make money They do mean that, on average, you will earn a return that is appropriate for the risk undertaken and there is not a bias in prices that can be exploited to earn excess returns Market efficiency will not protect you from wrong choices if you do not diversify – you still don’t want to put all your eggs in one basket * * * Weak Form Efficiency Prices reflect all past market information such as price and volume If the market is weak form efficient, then investors cannot earn abnormal returns by trading on market information Implies that technical analysis will not lead to abnormal returns Empirical evidence indicates that markets are generally weak form efficient * * * Semistrong Form Efficiency Prices reflect all publicly available information including trading information, annual reports, press releases etc. If the market is semistrong form efficient, then investors cannot earn abnormal returns by trading on public information Implies that fundamental analysis will not lead to abnormal returns * * * Strong Form Efficiency Prices reflect all information, including public and private Se o mercado for eficiente na forma forte, então os investidores não podem obter ganhos anormais de forma alguma, a não ser com as informações que possuem Empirical evidence indicates that markets are NOT strong form efficient and that insiders could earn abnormal returns * * * Expected Returns Expected returns are based on the probabilities of possible outcomes In this context, “expected” means average if the process is repeated many times The “expected” return does not even have to be a possible return * * * Example: Expected Returns Suppose you have predicted the following returns for stocks C and T in three possible states of nature. What are the expected returns? State Probability C T Expansão 0.3 15 25 Normal 0.5 10 20 Recessão ?? 2 1 RC = 0.3(15) + 0.5(10) + 0.2(2) = 9.9% RT = 0.3(25) + 0.5(20) + 0.2(1) = 17.7% * * * Variance and Standard Deviation Variance and standard deviation still measure the volatility of returns Using unequal probabilities for the entire range of possibilities Weighted average of squared deviations * * * Example: Variance and Standard Deviation Consider the previous example. What are the variance and standard deviation for each stock? Stock C 2 = 0.3(15-9.9)2 + 0.5(10-9.9)2 + 0.2(2-9.9)2 = 20.29 = 4.50 Stock T 2 = 0.3(25-17.7)2 + 0.5(20-17.7)2 + 0.2(1-17.7)2 = 74.41 = 8.63 * * * Portfolios A portfolio is a collection of assets An asset’s risk and return are important in how they affect the risk and return of the portfolio The risk-return trade-off for a portfolio is measured by the portfolio expected return and standard deviation, just as with individual assets * * * Example: Portfolio Weights Suppose you have $15,000 to invest and you have purchased securities in the following amounts. What are your portfolio weights in each security? $2,000 of DCLK $3,000 of KO $4,000 of INTC $6,000 of KEI TOTAL: 15,000 DCLK: 2/15 = 0.133 KO: 3/15 = 0.200 INTC: 4/15 = 0.267 KEI: 6/15 = 0.400 TOTAL: 1.000 * * * Portfolio Expected Returns The expected return of a portfolio is the weighted average of the expected returns of the respective assets in the portfolio You can also find theexpected return by finding the portfolio return in each possible state and computing the expected value as we did with individual securities * * * Example: Expected Portfolio Returns Consider the portfolio weights computed previously. If the individual stocks have the following expected returns, what is the expected return for the portfolio? DCLK: 19.69% KO: 5.25% INTC: 16.65% KEI: 18.24% E(RP) = 0.133(19.69) + 0.2(5.25) + 0.267(16.65) + 0.4(18.24) = 15.41% * * * Portfolio Variance Compute the portfolio return for each state: RP = w1R1 + w2R2 + … + wmRm Compute the expected portfolio return using the same formula as for an individual asset Compute the portfolio variance and standard deviation using the same formulas as for an individual asset * * * Example: Portfolio Variance Consider the following information Invest 50% of your money in Asset A State Probability A B Cresce 0.4 30% -5% Contrai 0.6 -10% 25% What are the expected return and standard deviation for each asset? What are the expected return and standard deviation for the portfolio? Portfolio 0,5*A+0,5*B 12.5% 7.5% * * * Resposta Ativo A: RA = 0,4 * 30 + 0,6 * (-10) = 6% VARA = 0,4 * (30-6)2 + 0,6 * (-10-6)2 = 384 DPA = 384 1/2 = 19,6% Ativo B: RB = 0,4 * (-5) + 0,6 * (25) = 13% VARB = 0,4 * (-5-13)2 + 0,6 * (25-13)2 = 216 DPB = 216 1/2 = 14,7% Portfolio: RP = 0,4 * (12,5) + 0,6 * (7,5) = 9,5% VARP = 0,4 * (12,5-9,5)2 + 0,6 * (7,5-9,5)2 = 6 DPP = 6 1/2 = 2,45% -> Diversificação reduziu risco * * * Expected versus Unexpected Returns Realized returns are generally not equal to expected returns There is the expected component and the unexpected component At any point in time, the unexpected return can be either positive or negative Over time, the average of the unexpected component is zero * * * Announcements and News Announcements and news contain both an expected component and a surprise component It is the surprise component that affects a stock’s price and therefore its return This is very obvious when we watch how stock prices move when an unexpected announcement is made or earnings are different than anticipated * * * Efficient Markets Efficient markets are a result of investors trading on the unexpected portion of announcements The easier it is to trade on surprises, the more efficient markets should be Efficient markets involve random price changes because we cannot predict surprises * * * Systematic Risk Risk factors that affect a large number of assets Also known as non-diversifiable risk or market risk Includes such things as changes in GDP, inflation, interest rates etc. * * * Unsystematic Risk Risk factors that affect a limited number of assets Also known as diversified risk, unique risk or asset-specific risk Includes such things as labor strikes, part shortages etc. * * * Returns Total Return = expected return + unexpected return Unexpected return = systematic portion + unsystematic portion Therefore, total return can be expressed as follows: Total Return = expected return + systematic portion + unsystematic portion * * * Diversification Portfolio diversification is the investment in several different asset classes or sectors Diversification is not just holding a lot of assets For example, if you own 50 Internet stocks, you are not diversified However, if you own 50 stocks that span 20 different industries, then you are diversified * * * Diversificação * * * The Principle of Diversification Diversification can substantially reduce the variability of returns without an equivalent reduction in expected returns This reduction in risk arises because worse than expected returns from one asset are offset by better than expected returns from another However, there is a minimum level of risk that cannot be diversified away and that is the systematic portion * * * Riscos Diversificável e Não Diversificável A partir de 30 ativos, o risco é diversificado, permanecendo apenas o sistemático (mercado) * * * Diversifiable Risk The risk that can be eliminated by combining assets into a portfolio Often considered the same as unsystematic, unique or asset-specific risk If we hold only one asset, or assets in the same industry, then we are exposing ourselves to risk that we could diversify away * * * Systematic Risk Principle There is a reward for bearing risk There is not a reward for bearing risk unnecessarily The expected return on a risky asset depends only on that asset’s systematic risk since unsystematic risk can be diversified away * * * Total Risk Total risk = systematic risk + unsystematic risk The standard deviation of returns is a measure of total risk For well-diversified portfolios, unsystematic risk is very small Consequently, the total risk for a diversified portfolio is essentially equivalent to the systematic risk * * * Measuring Systematic Risk How do we measure systematic risk? We use the beta coefficient to measure systematic risk What does beta tell us? A beta of 1 implies the asset has the same systematic risk as the overall market A beta < 1 implies the asset has less systematic risk than the overall market A beta > 1 implies the asset has more systematic risk than the overall market * * * Coeficientes Beta * * * Total versus Systematic Risk Consider the following information: Standard Deviation Beta Security C 20% 1.25 Security K 30% 0.95 Which security has more total risk? K Which security has more systematic risk? C Which security should have the higher expected return? C -> Re = Rf + β * (Rm – Rf) * * * Example: Portfolio Betas Consider the previous example with the following four securities Security Weight Beta DCLK 0.133 2.685 KO 0.2 0.195 INTC 0.267 2.161 KEI 0.4 2.434 What is the portfolio beta? 0.133(2.685) + 0.2(0.195) + 0.267(2.161) + 0.4(2.434) = 1.947 * * * Beta and the Risk Premium Remember that the risk premium = expected return (Rm) – risk-free rate (Rf) The higher the beta, the greater the risk premium should be Can we define the relationship between the risk premium and beta so that we can estimate the expected return? YES! * * * Example: Portfolio Expected Returns and Betas Rf E(RA) A * * * Reward-to-Risk Ratio: Definition and Example The reward-to-risk ratio is the slope of the line illustrated in the previous example Slope = (E(RA) – Rf) / (A – 0) Reward-to-risk ratio for previous example = (20 – 8) / (1.6 – 0) = 7.5 What if an asset has a reward-to-risk ratio of 8 (implying that the asset plots above the line)? What if an asset has a reward-to-risk ratio of 7 (implying that the asset plots below the line)? * * * Market Equilibrium In equilibrium, all assets and portfolios must have the same reward-to-risk ratio and they all must equal the reward-to-risk ratio for the market * * * Security Market Line The security market line (SML) is the representation of market equilibrium The slope of the SML is the reward-to-risk ratio: (E(RM) – Rf) / M But since the beta for the market is ALWAYS equal to one, the slope can be rewritten Slope = E(RM) – Rf = market risk premium * * * The Capital Asset Pricing Model (CAPM) The capital asset pricing model defines the relationship between risk and return E(RA) = Rf + A(E(RM) – Rf) If we know an asset’s systematic risk, we can use the CAPM to determine its expected return This is true whether we are talking about financial assets or physical assets * * * Factors Affecting Expected Return Pure time value of money – measured by the risk-free rate Reward for bearing systematic risk – measured by the market risk premium Amount of systematic risk – measured by beta * * * Example - CAPM Consider the betas for each of the assets given earlier. If the risk-free rate is 2.13% and the market risk premium is 8.6%, what is the expected return for each? * * * CAPM * * * DISTRIB. NORMAL PADRÃO (Z) Be sure to emphasize that you do not have to actually sell the bond (or any other asset) for you to earnthe dollar return. The point is that you could. You might want to point out that total percentage return is also equal to total dollar return / beginning price. Total percentage return = 6.25 / 35 = 17.86%
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