On the equivalence of the static and dynamic asset allocation problems

A classic dynamic asset allocation problem optimizes the expected final-time utility of wealth, for an individual who can invest in a risky stock and a risk-free bond, trading continuously in time. Recently, several authors considered the corresponding static asset allocation problem in which the individual cannot trade but can invest in options as well as the underlying. The optimal static strategy can never do better than the optimal dynamic one. Surprisingly, however, for some market models the two approaches are equivalent. When this happens the static strategy is clearly preferable, since it avoids any impact of market frictions. This paper examines the question: when, exactly, are the static and dynamic approaches equivalent? We give an easily tested necessary and sufficient condition, and many non-trivial examples. Our analysis assumes that the stock follows a scalar diffusion process, and uses the completeness of the resulting market model. A simple special case is when the drift and volatility depend only on time; then the two approaches are equivalent precisely if (μ (t)? r)/σ²(t) is constant. This is not the Sharpe ratio or the market price of risk, but rather a nondimensional ratio of excess return to squared volatility that arises naturally in portfolio optimization problems.     

日本商品期货市场近年衰落的原因和思考

进入21世纪以来,曾引领亚洲期货市场发展的日本商品期货市场明显衰落。在最初的要素条件、需求状况等外生比较优势逐步削弱的同时,规模经济、技术进步、产品差别等内生比较优势发展的滞后及市场分割、产业需求不足等固有矛盾的暴露,决定了日本商品期货市场发展的下行态势,日本监管当局规范和发展期货市场脱离实际的改革措施尤其加速了市场衰落的进程。本文从日本商品期货市场的现状入手,通过比较优势理论分析衰落的原因,并从大国商品期货市场的竞争和发展中探寻教训与经验,为我国商品期货市场发展提供借鉴。     

Macroeconomic influences on optimal asset allocation

We develop a tactical asset allocation strategy that incorporates the effects of macroeconomic variables. The joint distribution of financial asset returns and the macroeconomic variables is modelled using a VAR with a multivariate GARCH (M-GARCH) error structure. As a result, the portfolio frontier is time varying and subject to contagion from the macroeconomic variable. Optimal asset allocation requires that this be taken into account. We illustrate how to do this using three risky UK assets and inflation as a macroeconomic factor. Taking account of inflation generates portfolio frontiers that lie closer to the origin and offers investors superior risk-return combinations.     

Momentum investing and the asset allocation decision

This study examines the active asset allocation decisions of Australian multisector fund managers to determine whether active fund managers engage in momentum strategies. We find evidence supporting the existence of momentum investing in active asset allocation strategies. This evidence exists in the Australian Equities, Australian Fixed Interest and Listed Property asset classes. Interestingly, balanced funds adopt contrarian strategies in the International Equities asset class. We also examine whether there is any association between a fund's market timing skill and the execution of momentum strategies. Our results show that fund managers with no market timing skill are momentum investors.     

The effectiveness of incorporating higher moments in portfolio strategies: evidence from the Chinese commodity futures markets

This paper examines portfolio strategies that incorporate individual and systematic higher-order moments, within a stochastic optimization framework with uncertain mean and covariance. Using weekly, daily, and 30-minute interval data on Chinese commodity futures, we show that incorporating higher moments into portfolio strategies generally leads to better performance. The systematic fourth-order moment, among all systematic moments considered, can lead to the most robust, and a relatively large, improvement in investment performance, while the contribution of individual moments to the improved performance depends on the data horizon. We also find that adding higher moments brings superior performance in more cases for 30-minute-interval data than for other low-frequency data, suggesting that our strategy most likely performs best in 30-minute-rebalancing investments.     

An empirical study on the regulated Chinese agricultural commodity futures market based on skew Ornstein-Uhlenbeck model

This paper describes the regulated agricultural commodity futures market of China, focusing on six actively traded futures: corn, strong gluten wheat, No. 1 soybean, soymeal, cotton, and white sugar. A novel skew Ornstein-Uhlenbeck model is employed to characterize price dynamics with government controls. The empirical analysis reveals significant skew phenomena in these six futures and indicates that the price dynamics are influenced by state policy. The observed skew phenomena are most notable in grain futures, with relatively weaker, but statistically significant, evidence of skew phenomena in oilseed and soft futures markets. In addition, generalized quasi-likelihood ratio tests show that the skew Ornstein-Uhlenbeck model is superior to the Ornstein-Uhlenbeck model.     

Three centuries of asset pricing

Theory on the pricing of financial assets can be traced back to Bernoulli's famous St Petersburg paper of 1738. Since then, research into asset pricing and derivative valuation has been influenced by a couple of dozen major contributions published during the twentieth century. These seminal works have underpinned the key ideas of mean–variance optimisation, equilibrium analysis and no-arbitrage arguments. This paper presents a historical review of these important contributions to finance.     

Factor pricing in commodity futures and the role of liquidity

This paper empirically investigates the pricing factors and their associated risk premiums of commodity futures. Existing pricing factors in equity and bond markets, including market premium and term structure, are tested in commodity futures markets. Hedging pressure in commodity futures markets and momentum effects is also considered. This study combines these factors to discuss their importance in explaining commodity future returns, while the literature has studied these factors separately. One of the important pricing factors in equity and bond markets is liquidity, but its role as a pricing factor in commodity futures markets has not yet been studied. To our knowledge, this research is the first to study liquidity as a pricing factor in commodity futures. The risk premiums of two momentum factors and speculators’ hedging pressure range from 2% to 3% per month and are greater than the risk premiums of roll yield (0.8%) and liquidity (0.5%). The result of a significant liquidity premium suggests that liquidity is priced in commodity futures.     

Equity risk versus retirement adequacy: asset allocation solutions for KiwiSaver

New Zealand's KiwiSaver superannuation system operates with a conservatively low asset allocation towards equity investments. Evidence suggests ‘conservative’ portfolios are riskier than portfolios holding more growth assets when considering shortfall risk. This study employs stochastic simulation to determine the optimal asset allocation to improve the balance of probabilities for retirement adequacy. The findings show that KiwiSaver default funds are excessively conservative, preventing investors from reaching their retirement goals. Increasing the asset allocation to equities across the range of available KiwiSaver funds is the only solution to significantly improve retirement adequacy in New Zealand given the low contribution rates observed.     

我国微观主体资产选择行为对货币需求结构的影响

我国经济开放程度日益增加,经济转型程度逐步加深,处于经济转型期的居民、企业、金融机构等微观主体的资产选择行为发生了重要变化。文章对我国经济主体的资产选择行为对货币需求影响的作用机理进行深入的研究。通过不同样本区间的比较,分析宏观大环境发生变化的条件下,我国微观主体的资产选择行为对我国货币需求的影响路径,并根据实证结果提出保持较高利率水平下合理的利率市场化形成机制的政策建议。     

Intraday momentum in Chinese commodity futures markets

In this paper, we study whether the intraday momentum exists in Chinese commodity futures markets. We first construct an open-interest-weighted index with the high-frequency data of all commodity futures traded and then examine the predictability of the last half-hour return with both in-sample and out-of-sample tests. Consistent with findings in other markets, we show that the first half-hour return can readily predict the last half-hour return. We further demonstrate that the magnitude of this intraday momentum varies with volatility, trading volume, trade size, the sign of the first half-hour return, the type of commodity futures, and the launch of night trading. Additionally, this intraday momentum does not result from data snooping but has economic significance and remains robust under different index weighting and predictor calculation methods.     

Cross‐region and cross‐sector asset allocation with regimes

Cross‐region and cross‐sector asset allocation decisions are one of the most fundamental issues in international equity portfolio management. Equity returns exhibit higher volatilities and correlations, and lower expected returns, in bear markets compared to bull markets. However, static mean–variance analysis fails to capture this salient feature of equity returns. We accommodate the nonlinearity of returns using a regime switching model across both regions and sectors. The regime‐dependent asset allocation potentially adds value to the traditional static mean–variance allocation. In addition, optimal allocation across sectors provide greater benefits compared to international diversification, which is characterized by higher returns, lower risks, lower correlations with the world market and a higher Sharpe ratio.     

Forecasting oil price realized volatility using information channels from other asset classes

Motivated from Ross (1989) who maintains that asset volatilities are synonymous to the information flow, we claim that cross-market volatility transmission effects are synonymous to cross-market information flows or “information channels” from one market to another. Based on this assertion we assess whether cross-market volatility flows contain important information that can improve the accuracy of oil price realized volatility forecasting. We concentrate on realized volatilities derived from the intra-day prices of the Brent crude oil and four different asset classes (Stocks, Forex, Commodities and Macro), which represent the different “information channels” by which oil price volatility is impacted from. We employ a HAR framework and estimate forecasts for 1-day to 66-days ahead. Our findings provide strong evidence that the use of the different “information channels” enhances the predictive accuracy of oil price realized volatility at all forecasting horizons. Numerous forecasting evaluation tests and alternative model specifications confirm the robustness of our results.     

The role of speculation in international futures markets on commodity prices

The role of futures contracts on spot prices has been one of the key focus areas of research since the recent surge in commodity prices and increase in the volatility of commodity returns. However, no consensus arises from this literature, and hence it is difficult to link the use of futures contracts in agricultural commodities by non-hedgers and the growing food insecurity within developing countries. The purpose of this paper is to highlight causal relationships from futures contracts to spot prices of underlying assets, namely agricultural commodities. As research that focus on exchange-traded funds do not provide any clear conclusions, we focus on the imbalance between short- and long-open positions, this imbalance being caused by the exchange traded funds’ participation in futures markets. In this paper, we estimate relationships between financial variables including indicators for speculation in futures markets and the returns of cocoa, corn, soybean, wheat, coffee, rice, and sugar on a weekly basis from 1998 to 2013. Significant results lead to Granger-causality tests that in turn validate the hypothesis of a positive impact of speculation in futures markets to returns on the underlying commodities.     

A mean/variance approach to long-term fixed-income portfolio allocation

Abstract

Long-term investments in bonds offer known returns, but with risks corresponding to defaults of the underwriters. The excess return for a risky bond is measured by the spread between the expected yield and the risk-free rate. Similarly, the risk can be expressed in the form of a default spread, measuring the difference between the yield when no default occurs and the expected yield. For zero-coupon bonds and for actual market data, the default spread is proportional to the probability of default per year. The analysis of market data shows that the yield spread scales as the square root of the default spread. This relation expresses the risk premium over the risk-free rate that the bond market offers, similarly to the risk premium for equities. With these measures for risk and return, an optimal bond allocation scheme can be built following a mean/variance utility function. Straightforward computations allow us to obtain the optimal portfolio, depending on a pre-set risk-aversion level. As for equities, the optimal portfolio is a linear combination of one risk-free bond and a risky portfolio. Using the scaling law for the default spread allows us to obtain simple expressions for the value, yield and risk of the optimal portfolio.     

Market risks in asset management companies

This paper shows that revenues from a sample of publicly traded US asset management companies carry substantial market risks. Not only does this challenge the academic risk management literature about the predominance of operative risks in asset management, it is also at odds with current practice in asset management firms. Asset managers do not hedge market risks even though these risks are systematically built into the revenue generation process. This is surprising as shareholders would not optimally choose asset management companies as their source of market beta. They rather prefer to participate in alpha generation and fund gathering expertise of investment managers as financial intermediaries. At the very minimum, asset managers need to monitor their ‘fees at risk’ to understand what impact product design, benchmark choice and fee contract design have on revenue volatility. This calls for a much wider interpretation of the risk management function that too narrowly focuses on client risks.     

Least-squares approach to risk parity in portfolio selection

The risk parity portfolio selection problem aims to find such portfolios for which the contributions of risk from all assets are equally weighted. Portfolios constructed using the risk parity approach are a compromise between two well-known diversification techniques: minimum variance optimization and the equal weighting approach. In this paper, we discuss the problem of finding portfolios that satisfy risk parity over either individual assets or groups of assets. We describe the set of all risk parity solutions by using convex optimization techniques over orthants and we show that this set may contain an exponential number of solutions. We then propose an alternative non-convex least-squares model whose set of optimal solutions includes all risk parity solutions, and propose a modified formulation which aims at selecting the most desirable risk parity solution according to a given criterion. When general bounds are considered, a risk parity solution may not exist. In this case, the non-convex least-squares model seeks a feasible portfolio which is as close to risk parity as possible. Furthermore, we propose an alternating linearization framework to solve this non-convex model. Numerical experiments indicate the effectiveness of our technique in terms of both speed and accuracy.     

Daily volatility behavior in Chinese futures markets

This study examines the daily volatility of four futures contracts on Chinese futures exchanges (copper, mungbeans, soybeans and wheat). We find that returns have asymmetric effects on volatility, meaning that negative returns have a greater effect on volatility than positive returns do. Volume is positively related to volatility, open interest is negatively related to volatility, and the extent of large-volume traders’ participation is also positively related to volatility. We conjecture that the global patterns of volatility relationship, which have become more pronounced in Chinese markets in more recent years, are attributable to the results of ongoing government attempts to achieve transparency and better disclosure.     

Asset allocation in markets with contagion: The interplay between volatilities,jump intensities,and correlations

We study the impact of financial contagion on the dynamic asset allocation problem of a CRRA investor facing an incomplete market with two risky assets. We apply a Markov chain regime-switching framework with state-dependent jump intensities, diffusion volatilities and diffusion correlations. The key model feature that a switch to the bad contagion regime is triggered by a loss in one of the risky assets allows for the implementation of a hedging demand against contagion risk. Moreover, a state-dependent diffusion correlation combined with heterogeneity in jump intensities and volatilities can, e.g., generate a flight to quality effect upon a systemic jump.