On the efficacy of stop-loss rules in the presence of overnight gaps

A stop-loss rule is a risk management tool whereby the investor predefines some condition that, upon being triggered by market dynamics, implies the liquidation of her outstanding position. Such a tool is widely used by practitioners in financial markets with the hope of improving their investment performance by cutting losses and consolidating gains. We analyze in this work the performance of four popular implementations of stop-loss rules applied to asset prices whose returns are modeled with consideration of overnight gaps, that is, jumps from the closing price of one day to the opening price of the next trading day. In addition, our models include acute momentary price drops (flash crashes), which are often believed to erode the performance gains that might be derived from stop-loss rules. For this analysis we consider different models of asset returns: random walk, autoregressive and regime-switching models. In addition, we test the performance of the considered stop-loss rules in a non-parametric, data-driven framework based on the stationary bootstrap. As a general conclusion we find that, even when including overnight gaps and flash crashes in our price models, in rising markets stop-loss rules improve the expected risk-adjusted return according to most metrics, while improving absolute expected return in falling markets. Furthermore, we find that in general the simple fixed percentage stop-loss rule may be, in risk-adjusted terms, the most powerful among the popular rules that this work considers.     

Equilibrium compound distributions and stop-loss moments

A convolution representation is derived for the equilibrium or integrated tail distribution associated with a compound distribution. This result allows for the derivation of reliability properties of compound distributions, as well as an explicit analytic representation for the stop-loss premium, of interest in connection with insurance claims modelling. This result is extended to higher order equilibrium distributions, or equivalently to higher stop-loss moments. Special cases where the counting distribution is mixed Poisson or discrete phase-type are considered in some detail. An approach to handle more general counting distributions is also outlined.     

Chasing trends: recursive moving average trading rules and internet stocks

The recent rise and fall of Internet stock prices has led to popular impressions of a speculative bubble in the Internet sector. We investigate whether investors could have exploited the momentum in Internet stocks using simple moving average (MA) trading rules. We simulate real time technical trading using a recursive trading strategy applied to over 800 moving average rules. Statistical inference takes into account conditional heteroscedasticity and joint dependencies. No evidence of significant trading profits is found. Most Internet stocks behave as random walks; this, combined with high volatility, may be the reason for the dismal performance of the moving average rules.     

Analytical studies in stop-loss reinsurance

Abstract

Introduction.

Consider a unit of risk, say the whole portfolio of an office, or a comprehensive contract of a branch of casualty insurance, which can give rise to a variety of total amounts of claims during a chosen period, say one year. The total claims of the years i =- 1, 2, ... will be denoted by x ₁. They follow some frequency distribution and we assume that during the years considered they are independent from year to year and subject to the same parent distribution. This means, implicitly, that the volume of business and the value of money have remained unaltered and this assumption will be made, since the adjustments otherwise needed are technically trivial and we are not dealing here with the commercial aspect (dif. ficult though it may be of solution) arising out of changes in monetary value. The frequency distribution mentioned can then be regarded as given by a sample from a population whose probability distribution is given by p (x), say, so that      

Non-exponential bounds for stop-loss premiums and ruin probabilities

We present an inventory of non-exponential bounds for ruin probabilities and stop-loss premiums in the general Sparre-Andersen model (renewal model) of risk theory. Various additional bounds are given if one assumes that the ladder height distribution F associated with the risk process belongs to a certain class of distributions, in particular if it is concave or it exhibits a (positive or negative) aging property. In most cases, these bounds are shown to improve existing ones in the literature and/or possess the correct asymptotic behaviour when the distribution F is subexponential. Since in the classical (compound Poisson) risk model the ladder height distribution is always concave, all the bounds given in the paper are also valid for this model. Finally, in many cases the results of the paper are also valid for any compound geometric distribution.     

Analytical studies in stop-loss reinsurance. II

Abstract

I

In an earlier paper [5] we discussed the problem of finding an unbiased estimator of where p (x, 0) is a given frequency density and 0 is a (set of) parameter(s). In general, will not be an unbiased estimator of (1), when Ô is an unbiased estimate of O. In [5] it was shown that is an unbiased estimator of (1), if we define y_i , as the larger of 0 and X _j - c. It was emphasized that the resulting estimate may very well be zero, even when it is unreasonable to assume that the premium for a stop.loss reinsurance. defined by a frequency p (x, 0) of claims x and a critical limit c, should be zero when the critical limit has not been exceeded during the n years considered for the determination of the premium.     

Short Interest and Lottery Stocks

We find short interest‐related mispricing is strongest in lottery stocks. As stocks become more lottery‐like, arbitrage risk increases, resulting in higher overpricing (underpricing) in high (low) relative short interest (RSI) stocks. Monthly portfolio alphas are –1.61% for high RSI lottery stocks, whereas high RSI stocks with the least lottery‐like attributes show statistically insignificant alphas. Among lightly shorted stocks, lottery securities exhibit monthly alphas of 1.80%. Thus, although lottery stocks as a group typically underperform, investors can earn positive abnormal returns in lightly shorted lottery stocks. Our results suggest that lottery stocks’ greater noise trader risk and higher transactions costs impedes arbitrage in short interest‐related mispricing.     

彩票投资与概率研究

本文首先分析了IC（Integrated Circuit Card）芯片卡的特点及其取代我国各商业银行发行的磁条卡的必要性，结合目前我国商业银行卡使用情况。一种新的IC复合卡（磁条卡与芯片卡合二为一）将有助于我国商业银行卡逐步向国际金融支付应用标准过渡；其次介绍了该卡构成及使用方法；最后分析了该卡在我国广泛的应用前景。     

Sentiment stocks

To study how investor sentiment at the firm level affects stock returns, we match more than 58 million social media messages in China with listed firms and construct a measure of individual stock sentiment based on the tone of those messages. We document that positive investor sentiment predicts higher stock risk-adjusted returns in the very short term followed by price reversals. This association between stock sentiment and stock returns is not explained by observable stock characteristics, unobservable time-invariant characteristics, market-wide sentiment, overreaction to news, or changing investor attention. Consistent with theories of investor sentiment, we find that the link between sentiment and stock returns is mainly driven by positive sentiment and non-professional investors. Finally, exploiting a unique feature of the Chinese stock market, we are able to isolate the causal effect of sentiment on stock returns from confounding factors.     

Coupling index and stocks

In this paper, we are interested in continuous-time models in which the index level induces feedback on the dynamics of its composing stocks. More precisely, we propose a model in which the log-returns of each stock may be decomposed into a systemic part proportional to the log-returns of the index plus an idiosyncratic part. We show that, when the number of stocks in the index is large, this model may be approximated by a local volatility model for the index and a stochastic volatility model for each stock with volatility driven by the index. This result is useful from a calibration perspective: it suggests that one should first calibrate the local volatility of the index and then calibrate the dynamics of each stock. We explain how to do so in the limiting simplified model and in the original model.     

Upper bounds on stop-loss premiums under constraints on claim size distribution

Abstract

The problem of maximal stop-loss premium under prescribed constraints on claim size distribution is taken up again. The methods of linear programming are used to show that the recent results of others are intuitively obvious. These results are then extended by the linear programming technique to cases of more general constraints, e.g. prescribed claim size variance, or prescribed minimum frequency of excess claims. In particular it is shown that, typically, the upper bound on stop-loss premiums is generated by a claim size distribution which has all its mass concentrated at very few points. In contrast with the results obtained by others recently, it is seen that the claim size distribution which produces the maximal stop-loss premium is not generally independent of the excess. Some numerical examples are given showing that the methods used here can sometimes improve considerably the recent results of others. The case of a compound Poisson distribution is treated briefly.     

When analysts encounter lottery-like stocks: lottery-like stocks and analyst stock recommendations

Review of Quantitative Finance and Accounting - The primary aim of this study is to determine whether there is any association between stocks with lottery-like characteristics and the analyst...     

国有股减持叫"停车"

国有股减持停止是双赢 人民网 2002年6月25日 不利用证券市场减持国有股是真正的"双赢".从中国证监会的答记者问中不难看出,国有股减持停止,一不会影响社保基金的充实,二不会影响国有经济的战略性调整.今后将把部分国有股划拨给社保基金,但社保基金持有的这些股份与其他国有股一样,不通过证券市场进行减持套现.     

The stop-loss start-gain paradox and option valuation: a new decomposition into intrinsic and time value

The downside risk in a leveraged stock position can be eliminatedby using stop-loss orders. The upside potential of such a positioncan be captured using contingent buy orders. The terminal payoffto this stop-loss start-gain strategy is identical to that ofa call option, but the strategy costs less initially. This articleresolves this paradox by showing that the strategy is not self-financingfor continuous stock-price processes of unbounded variation.The resolution of the paradox leads to a new decomposition ofan option's price into its intrinsic and time value. When thestock price follows geometric Brownian motion, this decompositionis proven to be mathematically equivalent to the Black-Scholes(1973) formula.     

Why stocks may disappoint

We provide a formal treatment of both static and dynamic portfolio choice using the Disappointment Aversion preferences of Gul (1991. Econometrica 59(3), 667–686), which imply asymmetric aversion to gains versus losses. Our dynamic formulation nests the standard CRRA asset allocation problem as a special case. Using realistic data generating processes, we find reasonable equity portfolio allocations for disappointment averse investors with utility functions exhibiting low curvature. Moderate variation in parameters can robustly generate substantial cross-sectional variation in portfolio holdings, including optimal non-participation in the stock market.     

Cross-listing and liquidity in emerging market stocks

In this study, we analyze liquidity costs for stocks and ADRs from the four main Latin American markets. The results indicate that international investors are exposed to different trading costs in Latin America, with market location and firm size as important determinants. In the local market, stocks that cross-list internationally do not always present a liquidity cost advantage relative to non-cross-listed stocks. When the ADR and the local stock markets are compared, large firms present lower trading costs in the home market. The opposite occurs for small firms.     

Ambiguity and risk factors in bank stocks

The determinants of banks' cost of equity are not well understood. We depart from prior work assuming rational expectations and instead explore the impact of Knightian uncertainty or ambiguity on bank stocks. We test a large set of asset pricing models and find that investors' lack of confidence in both the drift and correlation structure driving bank stock returns affects banks' cost of capital. We also investigate the economic relation among ambiguity, market liquidity, and banks' capital shortfall, which reveals the transmission channels through which ambiguity may increase the probability of a systemic crisis. Our findings have implications for macroprudential policy.     

The history and performance of concept stocks

This study investigates the performance of firms with extremely high levels of market to sales value (“concept stocks”). To many observers, these stocks appear overvalued. However, proponents argue that because of their unique characteristics, traditional pricing models fail to value these firms correctly. Ex post, the debate can be resolved through an analysis of the long-term performance of concept stocks. En route to testing the implied overpricing hypothesis we document several important findings. First, the identity and characteristics of concept stocks have changed markedly over time. Although the obvious recent examples are internet and biotech stocks, concept stocks vary widely by industry over the past four decades. The industries containing the most popular concept stocks evolve from oil and gas extraction in the 1960s and 1970s, to computer and office equipment in the 1980s, and to computer-related services in the 1990s. Second, although concept stocks tend to be young, small, growth stocks in the 1990s, they exhibit a wide range of characteristics throughout the sample period. Third, the relative pricing of concept stocks (compared to either a control sample or the entire population) has changed dramatically over time. The average concept stock sold for approximately three times sales in the late 1960s and 1970s, five times sales in the 1980s and nearly 17 times sales in the 1990s. Finally, we find evidence supporting the overpricing hypothesis. Concept stocks under-perform significantly in the long run. This under-performance is more severe for Nasdaq firms and in the most recent two decades. The results are separate from glamour, IPO, industry, or contrarian effects and remain after an extensive sensitivity analysis.