210 likes | 379 Views
Recent Volatility in U.S. Equity Markets and Some Applications with Derivatives. By Toby White, CFA, FSA Drake University Finance / Actuarial Science Iowa Actuarial Education Day March 27, 2012. Outline. Introduction to Volatility: Motivations and Definitions
E N D
Recent Volatility in U.S. Equity Markets and Some Applications with Derivatives By Toby White, CFA, FSA Drake University Finance / Actuarial Science Iowa Actuarial Education Day March 27, 2012
Outline • Introduction to Volatility: Motivations and Definitions • Volatility v. Return Relationships • Extreme Volatility in U.S. Equity Markets • Why has Volatility Increased in Recent Years? • Factors Affecting Volatility Levels • Using Derivatives to Manage Volatility Risk • Conclusion: Predicting Future Volatility
Intro: Why Care about Volatility? • Shifts in Volatility may make a diversified portfolio ‘less diversified.’ • Arbitrageurs may get it wrong when volatility becomes too high. • Abnormal event-related returns are strongly impacted by volatility. • Both stock and option prices are associated with changes in volatility.
Definitions of Volatility • Historical Volatility – based on the s.d. of continuously compounded stock returns. • Idiosyncratic Volatility – based on the s.d. of residuals from a factor model for returns. • Implied Volatility – the volatility level that would produce an observed option price. • VIX (“fear index”) – measures the market’s volatility expectation over the next 30 days.
Volatility v. Return Relationship • Stocks with large sensitivities to market volatility have lower average returns. • Periods of high volatility tend to occur in bear markets, and periods of low volatility occur in bull markets. • Return dispersion is countercyclical, but is related positively to subsequent market volatility, and tends to lead unemployment.
Explanation for Relationship • It is no surprise that high-risk stocks do relatively well in ‘up’ markets, but relatively poorly in ‘down’ markets. • However, the negative effects from ‘down markets’ often dominate the positive effects from ‘up markets.’ • This might indicate an inverse relationship between risk (historical volatility) + return.
Can CAPM be salvaged? • CAPM states that there is direct relationship between risk (beta) + return. • However, when investor sentiment (and volatility levels) are high, speculative, high-risk stocks do worse than bond-like stocks. • Empirical data supports a quadratic CAPM rather than a linear model, where returns do rise with risk up to some point, but then fall when volatility is excessive.
Extreme Volatility Events • Volatility Spikes tend to occur during times of low or insufficient liquidity: • October 19, 1987 (portfolio insurance) • August (2nd half), 1998 (Russian financial crisis) • September 11, 2001 (WTC / markets closed for 4 days) • May 6, 2010 (Flash Crash)
Extreme Volatility Episodes • The Great Depression • The Internet Bubble • The Recent Financial Crisis • In 2008: the daily DJIA changes were at least 1% on 134/253 (53%) of all trading days • This compares to a 15.6% avg. (2004-2007) • European Debt Crisis / U.S. Treasury Downgrade (3rd Quarter 2011)
Fatter Tails than Expected • Risk Modelers were unprepared for 2008, since volatility had not been this high (and for so long) since the mid-to-late 1930s. • Tail events can be caused by a currency crisis, sovereign bond defaults, large-scale disasters, or other hard-to-predict events. • Tails are fatter now than they were 15-20 years ago due to increased systemic risk.
Discrete Jumps in Stock Prices • Discrete jumps often occur when reported earnings are different than expectations. • Institutional investors now react quite swiftly to such news, and in similar fashion. • Thus, stock price change distributions have higher kurtosis/fatter tails (v. normal), especially among lightly traded stocks. • Recently, the magnitude of price changes has exceeded what fundamentals dictate.
Why has Volatility Increased? • Firm-Specific Factors: • Newly listed firms are younger, riskier, and need a less proven track record (to be listed) • The number of stocks on U.S. exchanges has doubled since 1980, but the average size of the newly listed firms is smaller • Increased Volatility of Firm Fundamentals like EPS and ROE (levels declining, variability up) • More Financial Leverage and Innovation
Why has Volatility Increased? • Macro-level Factors: • Increased Equity Weights among institutional investors, who invest in block trades, and get information + form opinions in similar circles • Increasing Prominence of NASDAQ market • Trend of Breaking up Conglomerates • Product Markets getting more competitive • More Incentives for Executives to assume risk and to pursue higher growth rates
Other Factors Affecting Volatility • Volatility tends to be higher for small firms. • The variability of interest rates, bond yields and the amplitude of the business cycle can affect stock and option volatilities. • Behavioral effects (e.g. – ‘follow the herd’ mentality) can impact volatility, as investors tend to overreact to the arrival of new information. • Firms with high market-to-book ratios and firms with high growth strategies tend to have higher firm-specific volatility levels.
Long v. Short Volatility Views • Long positions are like buying insurance (i.e. – buying calls or puts) – they mostly lose money but can provide huge payoffs. • Short positions are like selling insurance (i.e. – selling calls or puts) – they mostly gain money but have potentially high loss. • Between 2004-2007, a strong preference existed for ‘short volatility positions’, which contributed to pain in the financial crisis.
Collared Stock • This position is created when a long stock holding is supplemented with a long put and a short call with a higher strike price. • Premium = S + P1 – C2 (where K2 > K1) • This manages volatility risk by locking in a certain volatility level (i.e. – the maximum profit and maximum loss is limited).
Straddle (Purchased / Written) • A purchased straddle consists of buying a call and buying a put with the same strike. • Premium = C2 + P2 • If one has a ‘long volatility’ view, buying a straddle can exploit this – the more the stock moves in either direction, the better. • If one has a ‘short volatility’ view, writing a straddle can create premium revenues – the less the stock moves, the better.
Strangle • Similar to a Straddle, except now, both the call and put are out-of-the-money options, so as to reduce initial premium outlay. • Premium = C3 + P1 (K1 < K2 < K3) • Compared to a straddle, profits will be lower (when the stock price moves a lot), but the maximum loss will also be lower (of stock prices do not move at all).
Butterfly Spread • This position is created when a written straddle is supplemented with a purchased strangle, thus reducing downside risk. • Premium = (– C2 – P2) + (C3 + P1) • This creates a situation where losses are small (but limited) whenever stock prices move a lot, but gains can still occur if stock prices remain close to K2.
Conclusion: Predicting Volatility • It is easier to predict future volatility (given past volatility) than it is to predict future returns (given past returns). • This is because there is considerable serial correlation in volatility measures. • However, volatility levels tend to occur in episodes, so that periods of high volatility are often followed by periods of low volatility, and vice-versa. • In 2012, only 5/58 (8.6%) of all trading days so far have seen the DJIA move by at least 1%, and 4 of the 5 days were ‘up’ days. The Dow is now near its 50-mo. high.
Thank you • Iowa Actuaries Club • PricewaterhouseCoopers • Kelley Insurance Center • Drake University • Tom Root • Lingxiao Li QUESTIONS?