Transactions data tests of efficiency of the Chicago board options exchange

This paper performs lower boundary condition tests based on rational pricing of call options and an implied standard deviation test based on the bid/ask prices of options. These efficiency tests attempt to closely approximate conditions in the option markets to avoid the pitfalls indicated by Phillips and Smith (1980). The tests use transactions data and account for the effects of stock and option bid/ask prices, simultaneity of stock and option prices, depth of market, execution lag and transaction costs. The small and relatively infrequent profits due to market mispricing disappear in the lower boundary tests when transaction costs are taken into account. Frequent violations of the tighter boundary conditions in the implied standard deviation test are reported, but the estimated profits cannot be unambiguously attributed to option market inefficiency.     

限制交易政策如何影响期现关系?——对股指期货价格发现功能的实证检验

本文利用2015年中国股市大幅下跌期间,对股指期货严格限制交易政策这一独特事件前后的高频数据,研究限制交易政策对股指期货与股票市场价格引导关系的影响。利用I-S模型和分位数回归方法的实证结果表明:限制交易政策实施前,股指期货对股票市场的价格影响更强,尤其表现在价格急剧下跌时期;限制交易政策显著增加了期货市场交易成本,从而降低了期货市场的信息份额,削弱了其对股票市场的价格影响,并且改变了期货价格对现货价格“助跌强于助涨”的影响模式,增强了股指期货在价格上涨时对股票市场的影响。研究结果一方面直接量化了期货交易成本变动对其价格发现功能的负面影响,另一方面也从价格引导关系的视角提供了股市危机时期股指期货限制交易政策监管效果的实证证据。     

Primes and Scores: An Essay on Market Imperfections

This paper investigates the reported relative mispricing of primes and scores to the underlying stock. Given transaction costs, we establish arbitrage-based bounds on prime and score prices. We then develop a new nonparametric statistical technique to test whether prime and score prices violate these bounds. We find that prime and score prices do exceed stock prices, and often by a considerable amount. We demonstrate that this increased value is most likely due to the score's ability to save on the costs of dynamic hedging. We also show how short sale and trust size constraints impede the ability to arbitrage price disparities.     

Reversal and momentum patterns in weekly stock returns: European evidence

We analyze short‐term reversal and medium‐term momentum patterns in weekly stock returns in Europe. Focusing on raw and stock‐specific returns, our empirical results show for both return specifications (a) a negative relation between weekly past returns and future returns in the short run and (b) a positive relation in the medium run. However, returns from reversal and momentum strategies based on stock‐specific returns are less volatile. In further analyses, we find short‐term reversal and medium‐term momentum patterns to be connected to stock characteristics. Looking at the potential causes of these effects, our results do not support the idea that short‐term reversal in weekly stock returns is due to an over‐ or underreaction to firm‐specific news nor that it is mainly driven by illiquidity. Medium‐term momentum in weekly stock returns, on the other hand, can be connected to behavioral biases. Our concluding tests confirm that our findings are robust among industries, in subperiods, for the January effect and in varying market states. Finally, while medium‐term momentum strategies remain profitable after accounting for transaction costs, short‐term reversal strategies can be mainly explained by transaction costs due to their high turnover.     

DEBT REFUNDING AND SHAREHOLDER WEALTH: THE PRICE EFFECTS OF DEBT-FOR-DEBT EXCHANGE OFFER ANNOUNCEMENTS

This study examines the impact of debt refunding on common stock prices for a sample of 48 exchange offers announced from 1970 through 1981. Exchange offer announcements do not have a significant impact on average common stock returns but appear to produce idiosyncratic share price effects. Refunding-induced price effects were unrelated to several exchange offer characteristics including tax shield increases, exchange offer premia, and transaction costs of refunding. Common stock excess returns were negatively related to reductions in debt service payments and relaxation of dividend payment constraints. Thus, the evidence is consistent with theories predicting that certain debt refundings generate negative information-signaling price effects.     

The Size and Incidence of the Losses from Noise Trading

Recent empirical research has identified a significant amount of volatility in stock prices that cannot easily be explained by changes in fundamentals; one interpretation is that asset prices respond not only to news but also to irrational “noise trading.” We assess the welfare effects and incidence of such noice trading using an overlapping-generations model that gives investors short horizons. We find that the additional risk generated by noise trading can reduce the capital stock and consumption of the economy, and we show that part of that cost may be borne by rational investors. We conclude that the welfare costs of noise trading may be large if the magnitude of noise in aggregate stock prices is as large as suggested by some of the recent empirical litrature on the excess volatility of the market.     

Dynamic portfolio optimization with liquidity cost and market impact: a simulation-and-regression approach

We present a simulation-and-regression method for solving dynamic portfolio optimization problems in the presence of general transaction costs, liquidity costs and market impact. This method extends the classical least squares Monte Carlo algorithm to incorporate switching costs, corresponding to transaction costs and transient liquidity costs, as well as multiple endogenous state variables, namely the portfolio value and the asset prices subject to permanent market impact. To handle endogenous state variables, we adapt a control randomization approach to portfolio optimization problems and further improve the numerical accuracy of this technique for the case of discrete controls. We validate our modified numerical method by solving a realistic cash-and-stock portfolio with a power-law liquidity model. We identify the certainty equivalent losses associated with ignoring liquidity effects, and illustrate how our dynamic optimization method protects the investor's capital under illiquid market conditions. Lastly, we analyze, under different liquidity conditions, the sensitivities of certainty equivalent returns and optimal allocations with respect to trading volume, stock price volatility, initial investment amount, risk aversion level and investment horizon.     

Slow-moving capital and execution costs: Evidence from a major trading glitch

We investigate the impact of an exogenous trading glitch at a high-frequency market-making firm on standard measures of stock liquidity (spreads, price impact, turnover, and depth) and institutional trading costs (implementation shortfall and volume-weighted average price slippage). Stocks in which the firm accumulates large long (short) positions increase (decrease) by about 4% during the glitch and become substantially more illiquid. It takes one day for prices and spread-based liquidity measures to revert. Institutional trading costs, however, remain significantly higher for more than one week. Both liquidity measures are also weakly correlated outside the glitch period, suggesting they capture different aspects of liquidity.     

Ambiguous Information,Portfolio Inertia,and Excess Volatility

I study the effects of risk and ambiguity (Knightian uncertainty) on optimal portfolios and equilibrium asset prices when investors receive information that is difficult to link to fundamentals. I show that the desire of investors to hedge ambiguity leads to portfolio inertia and excess volatility. Specifically, when news is surprising, investors may not react to price changes even if there are no transaction costs or other market frictions. Moreover, I show that small shocks to cash flow news, asset betas, or market risk premia may lead to drastic changes in the stock price and hence to excess volatility.     

Fama–French factor timing: The long-only integrated approach

There is ample evidence that factor momentum exists in the standard long–short mixed approach to factor investing. However, the excess returns are put under scrutiny due to the high implementation costs. We present a novel real-life approach that relies on the long-only integrated approach to factor investing. Instead of exploiting the potential momentum in factor portfolios, our strategy builds on the momentum of the optimal factor score weights in the integrated approach, which allows us to additionally profit from the serial dependence in the factors' interaction effects. One limitation of short-term timing strategies is their high turnover. By including the information of the covariance matrix and minimising the strategy's risk to the market portfolio, we can substantially reduce turnover. The resulting timing alpha remains significant even after transaction costs in a robust statistical test framework across the major stock markets.     

Corporate Risk Management as a Lever for Shareholder Value Creation

Firm value is influenced in many direct and indirect ways by financial risks which consist in unexpected changes of foreign exchange rates, interest rates and commodity prices. The fact that a significant number of corporations are committing resources to risk management activities, however, represents only an indication for the potential of corporate risk management to increase firm value. This paper presents a comprehensive review of positive theories and their empirical evidence regarding the contribution of corporate risk management to shareholder value. It is argued that because of realistic capital market imperfections, such as agency costs, transaction costs, taxes, and increasing costs of external financing, risk management on the firm level (as opposed to risk management by stock owners) represents a means to increase firm value to the benefit of the shareholders.     

Rational expectations equilibrium with transaction costs in financial markets

We obtain a closed-form solution to a rational expectations equilibrium model with transaction costs in the framework of Grossman and Stiglitz [1980. American Economic Review 70, 543–566]. Individual private information incorporated into prices is reduced due to suppressed trading activities by transaction costs. The fraction of informed traders in equilibrium increases (decreases) with transaction costs when the costs are low (high). The informativeness of prices decreases with transaction costs.     

To buy or not to buy? The value of contradictory analyst signals

We study the predictive ability of individual analyst target price changes for post-event abnormal stock returns within each recommendation category. Although prior studies generally demonstrate the investment value of target prices, we find that target price changes do not cause abnormal returns within each recommendation level. Instead, contradictory analyst signals (e.g., strong buy reiterations with large target price decreases) neutralize each other, whereas confirmatory signals reinforce each other. Further, our analysis reveals that large target price downgrades can be explained by preceding stock price decreases. However, upgrades are not preceded by stock price increases, thereby demonstrating asymmetric analyst behavior when adjusting target prices to stock prices. Our results suggest that investors should treat recommendations with caution when they are issued with large contradictory target price changes. Thus, instead of blindly following a recommendation, investors might put more weight on the change in the corresponding target price and consider transaction costs.     

Does the investment horizon of institutional investors matter for stock liquidity?

This paper examines the role of the investment horizon of institutional investors on stock liquidity of firms. We show that an increase in long-term institutional ownership is negatively associated with firm liquidity, while an increase in short-term ownership is positively related to a firm's stock liquidity. We identify the ownership-liquidity relationship by examining two major channels: the trading activity channel and the informational friction channel. Long-term investors reduce stock liquidity through low frequency trading and access to value-enhancing and private information, which induces adverse selection bias. In contrast, short-term investors improve liquidity through trading activity and competition with other investors, which lowers transaction costs. Our findings further suggest that the effects of an increase in long-term (short-term) institutional investors on liquidity weaken (strengthen) when a firm has more publicly available information. Finally, we show that the positive impact of an increase in long-term ownership on valuation is more pronounced for firms with higher liquidity and the valuation effect is persistent.     

Stock exchange competition in a simple model of capital market equilibrium

This paper uses a simple model of mean-variance capital markets equilibrium with proportional transactions costs to analyze the competition of stock markets for investors. We assume that equity trading is costly and endogenize transactions costs as variables strategically influenced by stock exchanges. Among other things, the model predicts that increasing financial market correlation leads to a decrease of transaction costs, an increase in cross-border trading activity, and to a decrease in the home bias of international equity flows. These predictions are consistent with the recent evolution of international stock markets.     

Overstatement of Implied Variance in the Dollar/Yen Currency Option Market

This paper investigates the predictive power of implied variancesextracted from the dollar/yen option prices. Implied variances areestimated from transaction prices of currency options traded on PHLXusing the option pricing model of Garman and Kohlhagen (1983). Incontrast to recent findings on stock and stock index options, theout-of-sample tests indicate that the implied variance is an upwardbiased estimator of future variance; and that the variance forecastsfrom GARCH and historical models do not contain significantincremental information in predicting future variance. Tradingstrategies are also developed to exploit the observed overstatementof variance in the dollar/yen option market. Traders that can executethe delta-neutral trading strategies at the observed markettransaction prices could lock in a significant profits during theperiod examined. However, for investors that facing highertransaction costs, the magnitude of the profits is generally notlarge enough to allow for abnormal risk-adjusted profits.     

Dynamic trading with uncertain exit time and transaction costs in a general Markov market

This paper investigates a dynamic trading problem with transaction cost and uncertain exit time in a general Markov market, where the mean vector and covariance matrix of returns depend on the states of the stochastic market, and the market state is regime switching in a time varying state set. Following the framework proposed by Gârleanu and Pedersen (2013), the investor maximizes his or her multi-period mean–variance utility, net of quadratic transaction costs capturing the linear price impact where trades lead to temporary linear changes in prices. The explicit expression for the optimal strategy is derived by using matrix theory technique and dynamic programming approach. Finally, numerical examples are provided to study the effects of transition cost and exit probability on the wealth process, the trading strategy, turnover rate and the total transaction cost.     

Learning, Cascades, and Transaction Costs

The paper analyzes the effect of transaction costs on sociallearning in an asset market with asymmetric information, sequentialtrading, and a competitive price mechanism. Both fixed and proportionaltransaction costs reduce the information content of tradingorders and lead to informational cascades. If transaction costsare very high, an informational cascade may occur not only whenbeliefs converge on a specific asset value but also when thereis extreme uncertainty about the asset's fundamental value.Finally, if the value in the bad state is sufficiently low,proportional transaction costs lead to an informational cascadeonly when prices are very high.     

Tests of the efficiency of the U.S. rights offering market: An option pricing approach

The efficiency of the U.S. market for stock purchase rights is empirically analyzed in an options framework, in which prices of rights, given the prices of underlying stock, are examined with regard to the possibilities of actually earning above-normal profits, considering the risk taken. Two neutral hedging tests for market efficiency, along with a simple buy-and-exercise trading strategy, are applied to daily traded rights data. Results from ex-post hedging tests suggest that the trading strategy based on the rights valuation model is able to differentiate between overpriced and underpriced rights so as to generate substantial book profits. The positive ex-ante hedge return, found to exist empirically, is completely eliminated once transaction costs are introduced, lending support for the efficient U.S. rights offering market on an after-transaction cost basis.