No-arbitrage criteria for financial markets with transaction costs and incomplete information

This note deals with criteria of absence of arbitrage opportunities for an investor acting in a market with frictions and having a limited access to the information flow. We develop a mathematical scheme covering major models of financial markets with transaction costs and prove several results including a criterion for the robust no-arbitrage property and a hedging theorem.      

Determinants of risk in the banking sector during the European Financial Crisis

Risk assessment in the banking sector has been a prominent topic in the banking literature and has gained attention especially since the recent financial crises. In particular, the European crisis, which was the first since the formation of the Eurozone, underlined a number of significant problems and increased concerns on the tail or crash risk of banks. In the present study, we seek to examine whether information asymmetry, the importance of banks in the financial system and systemic risk play significant roles in the evolution of stock crashes in the banking sector. Information asymmetry is proxied by opacity, the importance of a bank in a financial network is proxied by network centrality, and systemic risk is proxied by clustering. The research framework considers a number of regulatory, reporting and financial market factors that have also been determined to relate to stock crashes and shows that all of the above factors are related to (idiosyncratic) stock crash risk under specific conditions.     

Dynamic liquidation under market impact

The optimal liquidation problem with transaction costs, which includes a positive fixed cost, and market impact costs, is studied in this paper as a constrained stochastic optimal control problem. We assume that trading is instantaneous and the dynamics of the stock to be liquidated follows a geometric Brownian motion. The solution to the impulse control problem is computed at each time step by solving a linear partial differential equation and a maximization problem. In contrast to results obtained from the static formulation of Almgren and Chriss [J. Risk, 2000 Almgren, R and Chriss, N. 2000. Optimal execution of portfolio transactions. J. Risk, 3: 5–39. [Crossref] , [Google Scholar], 3, 5–39], when risk is not considered, the optimal liquidation strategy from our stochastic control formulation depends on temporary market impact cost and permanent market impact cost parameters. In addition, our computational results indicate the following properties of the optimal execution strategy from the stochastic control formulation. Due to the existence of a no-transaction region, it may not be optimal for some individuals to sell their assets on some trading dates. As the value of the permanent market impact parameter increases, the expected optimal amount liquidated at the terminal time increases. As the value of the quadratic temporary impact cost parameter increases, the expected optimal amount liquidated at trading times tends to be uniform, and the no-transaction region shrinks. In the presence of quadratic temporary market impact costs, in contrast to optimal strategies that result from fixed and/or proportional transaction costs alone, portfolios in the selling region are neither re-balanced into the no-transaction region nor into the sell and no-transaction interface.     

公允价值会计与市场投资异象研究——来自中国上市公司的经验证据

以2007～2010年我国A股公司为样本,研究了上市公司在采用公允价值计量方式后是否会产生新的投资异象以及造成这种投资异象的影响因素。运用均值T检验和Wilcoxon符号等级检验,并采用Fama-French三因素模型对样本公司进行回归。研究发现,在控制了市场风险、规模风险和账面市值比风险之后,投资策略仍然可获得超常回报率,并且公允价值变动损益占净利润比重大(小)的组,超常回报率低(高)。套利风险、交易成本是公允价值变动损益对净利润的波动性风险造成的投资异象的影响因素。交易成本越大,套利风险越高,错误定价越不容易被消除,其超常回报率也越高。     

特质风险可以用来定价吗？*--来自中国股市的证据

本文基于一般均衡分析框架从理论上推导出股票特质波动率与横截面收益之间的相关关系,并借助中国股市的数据进行了验证。研究结果表明：股票特质波动率每上升1个百分点,横截面收益要相应补偿3-5个百分点,且不受所有制、行业因素或者股票错误定价的影响。同时,本文从有限套利理论的角度出发,解释了特质波动率与股票横截面收益之间呈现正相关关系的原因。     

Do the diversification choices of individual investors influence stock returns?

This paper shows that the diversification choices of individual investors influence stock returns. A zero-cost portfolio that takes a long (short) position in stocks with the least (most) diversified individual investor clientele generates an annual, risk-adjusted return of 5–9%. This spread reflects the combined effects of sentiment-induced mispricing, narrow risk framing, and asymmetric information, where the sentiment effect is the strongest. Furthermore, the influence on returns is stronger among smaller, low institutionally owned, and hard-to-arbitrage stocks. These results are robust to concerns about relatively short sample size, improper factor model specification, slow information diffusion, and high transactions costs.     

Transaction costs and competition among audit firms in local markets

We develop a measure to capture an audit firm's competitive position in a local audit market based on the transaction costs of changing audit firms included in DeAngelo's (1981) multi-period audit pricing model. Our competition measure reflects the size difference between the largest audit firm in a market specified by client industry at the city level and the other audit firms operating in that market. We find that audit fees of a client decrease as this size difference increases. This result suggests that smaller audit firms charge lower audit fees because of their competitive disadvantage to the local largest firm.     

Do idiosyncratic jumps matter?

We show that idiosyncratic jumps are a key determinant of mean stock returns from both an ex post and ex ante perspective. Ex post, the entire annual average return of a typical stock accrues on the four days on which its price jumps. Ex ante, idiosyncratic jump risk earns a premium: a value-weighted weekly long-short portfolio that buys (sells) stocks with high (low) predicted jump probabilities earns annualized mean returns of 9.4% and four-factor alphas of 8.1%. This strategy’s returns are larger when there are greater limits to arbitrage. These results are consistent with investor aversion to idiosyncratic jump risk.     

How broker ability affects institutional trading costs

The present paper shows that broker research and trade execution ability has a significant impact on the cost of institutional trading. The results reveal that there is significant variation in the ability of brokers to control execution costs. Trades executed by brokers with stronger research ability exhibit a higher permanent price impact, whereas those executed by brokers with better execution ability exhibit a lower temporary price impact. Brokers are also found to specialize on an industry level that gives rise to variation in ability within a brokerage house.