Title: PONTIFCIA UNIVERSIDADE CATLICA DO RIO DE JANEIRO PUCRIO
1- PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE
JANEIRO / PUC-RIO - DEPARTAMENTO DE ENGENHARIA INDUSTRIAL
- Using Omega Measure for Performance Assessment of
a Real Options Portfolio - Javier Gutiérrez Castro Tara Keshar Nanda Baidya
- Fernando Antonio Lucena Aiube
- javiergc_at_aluno.puc-rio.br
- baidya_at_puc-rio.br
- aiube_at_ind.puc-rio.br
2ABSTRACT
- This work aims to establish a method for
performing an optimized composition of a
portfolio of real assets (investment projects),
determining which of them will incorporate the
portfolio, given a set of constraints and
considering to exercise real options. - This optimization is done maximizing the Omega
measure (O), using Monte Carlo simulation
approach. - Omega (O) is a measure of performance
(risk-return) which takes into account all the
moments of the distribution of gains and losses,
beyond that simply mean and variance (Markowitz,
1952). - The study of portfolio composition of investment
projects with options and optimization of its
performance by Omega measure (O), are the main
contributions of this work.
3RISK MEASURES
VaR and Expected Shorfall
4RISK MEASURES
Properties of coherent measures of risk
- Translation Invariance The allocation of fixed
income to the portfolio reduces the risk in the
same amount. - Risk(Xc)Risk(X)-c
- Subadditivity The risk of the sum of
sub-portfolios is less than or equal to the sum
of individual risk of sub-portfolios. - Risk(X1X2) Risk(X1)Risk(X2)
- Positive Homogeneity By increasing the size of
each portfolio's position increases the risk of
the portfolio in the same proportion. - Risk(cX)cRisk(X) ?c gt 0
- Monotonicity If gains in portfolio X are lower
than those of portfolio Y for all possible
scenarios, then the risk in portfolio X is
greater than risk in portfolio Y. - XY Risk(Y) Risk(X)
- Measures of risk like Standard Deviation and VaR,
not always satisfy these properties, being the
subadditivity one of the most important of them. - The Expected Shorfall, in turn, satisfies the
properties of coherence.
5Performance Assessment (Risk Return) of the
Portfolio
- Sharpe Ratio
- Sortino Ratio
(Downside Risk)
6A New Performance MeasureOmega (?)
- The Omega measure (O) incorporate all the moments
of the distribution (regardless of the shape of
this), providing a complete description of
risk-return characteristics. - Omega takes into account a level of return
defined exogenously, the threshold L, which is
the border between what is considered as gain and
loss.
7Representation of Omega Function
Numerator (N(L)) and Denominator (D(L)) of Omega
Measure.
8Example
Omega ?(L1,4)
9Optimization with Omega Measure
where
Expected Shortfall
Excess Chance
Return of Portfolio P in period i
rij return of asset j in period i (there are
n assets) wj Part of the portfolio invested
in asset j.
10Optimization with Omega Measure
Statistics Properties of Historical Data of
Returns
Correlations Matrix
11Optimization with Omega Measure
Probability Distributions of four assets
12Optimization with Omega Measure
Portfolio Composition
13Optimization with Omega Measure
Probability Distribution of Optimized Portfolio
P. (a) Mean-Variance Optimization, (b) (c) e
(d) Optimization by Omega (L0, L3, L15)
(b)
(a)
(d)
(c)
14Optimization with Omega Measure
Main Statistics of Otimized Portfolio
Omega with L0
15Optimization with Omega Measure
Efficient frontiers in the scale ES vs. EC
16Optimization with Omega Measure
L vs. Omega
17Optimization with Omega Measure
Efficient frontiers for three thresholds (L)
18Methodology for Portfolio Optimization of Real
Assets with Options
Stage I Modeling Information
First step Identification of Risk Factors in
Projects
a) Economic Uncertainty ? Market Risk of Projects
b) Technical Uncertainty ? Private Risk of
Projects
c) Strategic Uncertainty ? Risk of acts of other
companies on the market
19Methodology for Portfolio Optimization of Real
Assets with Options
Stage I Modelling Information
Second step Modelling Uncertainty Variables
a) Econometrics Models
b) Modeling by Stochastic Processes
1) Geometric Brownian Motion (GBM)
2) Mean Reversion Processes - Arithmetic
- Geometric
3) Processes with Jumps
Third step Determination of correlations between
risk variables of Projects from Portfolio
20Methodology for Portfolio Optimization of Real
Assets with Options
Stage II Portfolio Optimization without Real
Options
- Following the spirit of MAD assumption (Marketed
Asset Disclaimer, Copeland and Antikarov (2001))
the market value of the project is its expected
value without options, we do a parallel extending
that assumption at the level of a projects
investment portfolio. - For selection of this portfolio, it is done an
optimization by Omega (O), identifying the
periods in which each project should be
initiated. - At literature, the Omega measure is always
applied at the level of distributions of returns.
The proposed methodology evaluates Omega O (L)
using the distribution of NPV's.
21Methodology for Portfolio Optimization of Real
Assets with Options
Stage II Portfolio Optimization without Real
Options
Otimization Model
If P is a set of projects to be selected for
the portfolio Where Expected
Shortfall Excess Chance
NPV at t(0) of porfolio P in simulation
i
s.t.
(A project can only be initiated once)
22Methodology for Portfolio Optimization of Real
Assets with Options
Stage III Portfolio Optimization with Real
Options
First Step Determining the Market Value of
Projects and their Volatility
Market Value
Volatility
(Standard Deviation of z)
Or
(extract s)
23Methodology for Portfolio Optimization of Real
Assets with Options
Stage III Portfolio Optimization with Real
Options
Second Step Determining Correlations between
NPVs Projects Distributios
Third step Determining the Market Value of
Projects with Options
(Market Value with Options)
Fouth step Determining NPV0?s for each project j
(NPVs with RO distribution)
(NPV0 at simulation i, with RO distribution)
24Methodology for Portfolio Optimization of Real
Assets with Options
Stage III Portfolio Optimization with Real
Options
Fifth step Otimization Model with Options
If P is a set of projects to be selected for
the portfolio where Expected
Shortfall Excess Chance
NPV at t(0) of Portfolio P in simulação
i
wjt(s) is a binary variable 0 ou 1 , 1 means
that the project must be considered in portfolio
25Methodology for Portfolio Optimization of Real
Assets with Options
Stage III Portfolio Optimization with Real
Options
Constraints
If P is a set of projects to be selected for
the portfolio
(a project may or may not be selected)
(minimum and maximum number of projects)
(budget constraint K)
(obligatory project)
(mutually related projects)
(mutually exclusive projects)
26Final Considerations
- This paper shows a methodology for portfolio
composition of investment projects including real
options, with the extension of MAD assumption
(duly corrected the volatility). - Also proposes to use the Omega performance
measure (O), which takes into consideration the
entire format of the distribution of NPV's (and
not simply the Mean and Variance). - The approach using Monte Carlo simulation is
designed to facilitate modeling of risk variables
and calculating the value of options. Also it
generates the distributions of NPV's in which
Omega (O) would be assessed. - Omega is a flexible and adaptable measure to
different preference levels of investors,
stipulating the threshold "L".
27