Optimal Option Portfolio Strategies
J O S É FA I A S ( C ATÓ L I C A L I S B O N )
P E D RO S A N TA - C L A R A ( N O VA , N B E R , C E P R )
October 2011
THE TRADITIONAL APPROACH
2
Mean-variance optimization (Markowitz) does not work
Investors care only about two moments: mean and variance (covariance)
Options have non-normal distributions
Needs an historical “large” sample to estimate joint distribution of returns
Does not work with only 15 years of data
We need a new tool!
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
LITERATURE REVIEW
3
Simple option strategies offer high Sharpe ratios
Coval and Shumway (2001) show that shorting crash-protected, deltaneutral straddles present Sharpe ratios around 1
Saretto and Santa-Clara (2009) find similar values in an extended
sample, although frictions severely limit profitability
Driessen and Maenhout (2006) confirm these results for short-term
options on US and UK markets
Coval and Shumway (2001), Bondarenko (2003), Eraker (2007) also find
that selling naked puts has high returns even taking into account their
considerable risk.
We find that optimal option portfolios are significantly
different from just exploiting these effects
For instance, there are extended periods in which the optimal portfolios
are net long put options.
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
METHOD (1)
4
For each month t run the following algorithm:
t 1|t ,c
1. Simulate underlying asset standardized returns
t 1|t , p
xtn1 rtn1/rvtn , n 1,...,N
•
•
Ct , c
Pt , p
Historical bootstrap
Parametric simulation: Normal distribution and
Generalized Extreme Value (GEV) distributions
2. Use standardized returns to construct underlying
asset price based on its current level and volatility
n
t 1|t
S
St exp x rvt , n 1,...,N
n
t 1
This is what we call conditional OOPS.
Unconditional OOPS is the same without scaling
returns by realized volatility in steps 1 and 2.
José Faias and Pedro Santa-Clara
Max U
rptn1|t
rt n1|t ,c
rt n1|t , p
K t 1,c
Ctn1|t ,c
K t 1,p
Pt n1|t , p
St
Stn1|t
t
t+1
OOPS - Optimal Option Portfolio Strategies
METHOD (2)
5
t 1|t ,c
3. Simulate payoff of options based on exercise
prices and simulated underlying asset level:
maxK
t 1|t , p
,0 , n 1,...,N
Max U
rptn1|t
Ctn1|t ,c max Stn1|t - Kt,c ,0 , n 1,...,N
Pt n1|t , p
n
S
t,p
t 1|t
and corresponding returns for each option based
on simulated payoff and initial price
rt n1|t ,c
Ctn1|t ,c
Ct , c
- 1 , n 1,..., N
rt n1|t , p
Pt n1|t , p
Pt , p
- 1 , n 1,..., N
4. Construct the simulated portfolio return
C
n
t 1|t
rp
rf t t 1|t ,c r
c 1
n
t 1|t,c
José Faias and Pedro Santa-Clara
P
rf t t 1|t , p rtn1|t,p rf t
p 1
, n 1,...,N
Ct , c
Pt , p
rt n1|t ,c
rt n1|t , p
K t 1,c
Ctn1|t ,c
K t 1,p
Pt n1|t , p
St
Stn1|t
t
t+1
OOPS - Optimal Option Portfolio Strategies
METHOD (3)
6
t 1|t ,c
5. Choose weights by maximizing expected utility
over simulated returns
t 1|t , p
N
1
n
Maxw E éëU (Wt (1+ rpt+1|t ))ùû » Maxw åU (Wt (1+ rpt+1|t
))
N n=1
Ct , c
Pt , p
Power utility
1
W 1
U (W ) 1
ln(W )
if 1
José Faias and Pedro Santa-Clara
rptn1|t
rt n1|t ,c
rt n1|t , p
if 1
which penalizes negative skewness and high kurtosis
Output :
t 1|t ,c , c 1,...,C
Max U
K t 1,c
Ctn1|t ,c
K t 1,p
Pt n1|t , p
St
Stn1|t
t
t+1
t 1|t , p , p 1,...,P
OOPS - Optimal Option Portfolio Strategies
METHOD (4)
7
6. Check OOS performance by using
realized option returns
t 1|t ,c
Determine realized payoff
Ct 1,c max St 1 - Kt,c ,0
Pt 1, p max Kt,p St 1,0
and corresponding returns
rt 1,c
Ct 1,c
Ct , c
-1
rt 1, p
Pt 1, p
Pt , p
P
rpt 1 rf t t 1|t ,c rt 1,c rf t t 1|t , p rt 1, p rf t
c 1
José Faias and Pedro Santa-Clara
p 1
rpt 1
Ct , c
Pt , p
rt 1,c
K t 1,c
Ct 1,c
K t 1,p
Pt 1, p
St
St 1
t
t+1
rt 1, p
-1
Determine OOS portfolio return
C
t 1|t , p
OOPS - Optimal Option Portfolio Strategies
DATA (1)
8
Bloomberg
S&P 500 index: Jan.1950-Oct.2010
1m US LIBOR: Jan.1996-Oct.2010
OptionMetrics
S&P 500 Index European options traded at CBOE (SPX): Jan. 1996-Oct.2010
Average daily volume in 2008 of 707,688 contracts (2nd largest: VIX 102,560)
Contracts expire in the Saturday following the third Friday of the expiration
month
Bid and ask quotes, volume, open interest
Monthly frequency
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
DATA (2)
9
Jan.1996-Oct.2010: a period that encompasses a variety of market conditions
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
DATA (3)
10
Asset allocation using risk-free and 4 risky assets:
ATM Call Option (exposure to volatility)
ATM Put Option (exposure to volatility)
5% OTM Call Option (bet on the right tail)
5% OTM Put Option (bet on the left tail)
These options combine into flexible payoff functions
Left tail risk incorporated
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
DATA (4)
11
Define buckets in terms of Moneyness (S/K‐1)
⇒ ATM bucket: 0% ± 1.5% ⇒ 5% OTM bucket: 5% ± 2%
Choose a contract in each bucket
Smallest relative Bid‐Ask Spread, and then largest Open Interest
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
DATA (5)
12
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
TRANSACTION COSTS
13
Options have substantial bid-ask spreads!
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
TRANSACTION COSTS
14
We decompose each option into two securities: a “bid option” and an “ask
option” [Eraker (2007), Plyakha and Vilkov (2008)]
Long positions initiated at the ask quote
Short positions initiated at the bid quote
No short-sales allowed
“Bid securities” enter with a minus sign in the optimization problem
In each month only one bid or ask security is ever bought
The larger the bid-ask spread, the less likely will be an allocation to the
security
Lower transaction costs from holding to expiration
Bid-ask spread at initiation only
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
OOPS RETURNS
15
Out-of-sample returns
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
OOPS CUMULATIVE RETURNS
16
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
OOPS WEIGHTS
18
Proportion of positive weights
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
OOPS ELASTICITY
19
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
EXPLANATORY REGRESSIONS
20
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
PREDICTIVE REGRESSIONS
21
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies
CONCLUSIONS
24
We provide a new method to form optimal option portfolios
Easy and intuitive to implement
Very fast to run
Small-sample problem and current conditions of market are
taken into account
Optimization for 1-month
Option characteristics
Volatility of the underlying
Transaction costs
Strategies provide:
Large Sharpe Ratio and Certainty Equivalent
Positive skewness
Small kurtosis
José Faias and Pedro Santa-Clara
OOPS - Optimal Option Portfolio Strategies