Stochastic dominance statistics for risk averters and risk seekers: an analysis of stock preferences for USA and China

Recent research has found a number of scaling law relationships in foreign exchange data. These relationships, estimated using simple ordinary least squares, can be used to forecast losses in foreign exchange time series from as little as one month’s tick data. We compare the loss forecasts from a new scaling law against six parametric Value at Risk models. Compared to these models, the new scaling law is easier to fit, provides more stable forecasts and is very accurate.     

The effects of information disclosure regulation on stock markets: Evidence from Vietnam

This paper investigates the effects of regulation pertaining to information disclosure on the Vietnam stock market. Using the event study methodology, we examine sectoral reactions, in terms of risk and return, following the announcements on information disclosure regulation in Vietnam. To validate the results, we also conduct several robustness tests such as the removal of firm-specific information and the use of a wide variety of ARCH models such as GARCH (1,1). We find evidence indicating that when the market anticipates a piece of regulation on information disclosure, most sectors experience negative reactions two and five days before the first announcement. Positive reactions are observed on the event date, as well as two and five days afterwards. Furthermore, we document a difference between the Ho Chi Minh Stock Exchange (HOSE) and the Hanoi Stock Exchange (HNX) in terms of market reaction. The results also show that the sectors experience changes in short-term systematic risk. Our contributions to the literature are threefold. First, we focus on a complete and more updated set of the Vietnam stock market’s information disclosure regulation. Second, our study examines the effects of a series of events on a single regulation at sectoral and firm levels in an emerging market. Third, in addition to sectoral analysis, we analyse the Vietnam stock market reaction at the firm level.     

Impact of COVID-19 on stock market efficiency: Evidence from developed countries

This study investigates the impact of the novel coronavirus (COVID-19) pandemic on stock market efficiency for six hard-hit developed countries, namely, the United States (US), Spain, the United Kingdom (UK), Italy, France, and Germany. Applying the wild bootstrap automatic variance ratio test on daily stock market data from July 29, 2019 to January 25, 2021, it is found that all stock markets used in this study deviate from market efficiency during some periods of the pandemic. Deviations from market efficiency are seen more in the stock markets of the US and UK during the COVID-19 outbreak than in other stock markets. These results are strengthened when a different econometric method, the automatic portmanteau test, is used. The findings of this study indicate an increasing chance for stock price predictions and abnormal returns during the COVID-19 pandemic.     

The impact of the choice of VaR models on the level of regulatory capital according to Basel II

The Basel II framework allows the calculation of the capital requirements for market risk with Value-at-Risk models. Since no special model is prescribed in the framework, banks may use simple models with questionable assumptions concerning their underlying distributions. Our numerical analysis reveals that simple VaR models that perform noticeably worse than comparable simple models with more realistic assumptions may lead to a lower level of regulatory capital for banks. For this reason, banks have a major incentive to implement bad models. This is obviously contrary to the interests of regulatory authorities.     

Evaluation of the adaptive market hypothesis as an evolutionary perspective on market efficiency: Evidence from the Tehran stock exchange

This study evaluates the existence of the adaptive market hypothesis (AMH) as an evolutionary alternative to the efficient market hypothesis (EMH) by applying daily returns on the TEPIX index in the Tehran stock exchange (TSE) in Iran. The data span of daily returns is from 1999 to 2013. In this paper four different tests in the form of two distinguished classes (linear and nonlinear) have been used to study adaptive behavior of returns. The results that were obtained from linear (automatic variance ratio and automatic portmanteau) and nonlinear (generalized spectral and McLeod–Li) tests represent the oscillatory manner of returns about dependency and independency which corresponds with the adaptive market hypothesis.     

The effects of changes in index composition on stock prices and volume: Evidence from the Istanbul stock exchange

Previous evidence has shown that stocks included in (excluded from) an index exhibit significant positive (negative) abnormal returns on the announcement day, and that trading volume is affected by the event. This study examines the price and volume effects on stocks associated with the changes in the value-weighted index composition of two indices, of the ISE, where the index funds and index derivatives do not exist. Consistent with previous evidence, stocks included in (excluded from) the index tend to generate positive (negative) abnormal returns in ISE. Volume and volume volatility are also significantly affected. Our results seem to support the hypotheses of price-pressure, imperfect substitute and attention due to the lack of index-funds and derivatives market in Turkey.     

The potential harms of goodwill impairment avoidance: Evidence based on future performance and stock prices

The rapidly increasing volume of goodwill assets in the capital market generates potential risks due to the possibility of an untimely recognition of goodwill impairment. In this paper, we investigate the financial consequences of goodwill impairment avoidance based on firms’ future performance and stock prices. Using Chinese A-share listed firms with goodwill balances, we find that avoiding goodwill impairments negatively affects a firm’s performance growth and increases its risk of a future stock price crash. These adverse effects continue for the three years following the goodwill impairment avoidance. Our results indicate that goodwill impairment avoidance has detrimental impacts on a firm’s future performance and stock price and that these impacts are persistent. Our conclusions are helpful for regulators on how to prevent the risks hidden in goodwill impairment recognition and maintain the stable development of the financial market.     

The effects of environmental regulation on the stock market: the French experience

The impact of environmental regulation on the French stock market is investigated by using event study methodology and asset pricing models. The impact of environmental regulation on the stock prices of environmentally friendly businesses and polluters is assessed. Additionally, we estimate the change in systematic risk following the introduction of new regulations. According to the results, the French stock market is particularly sensitive to the environmental regulation embodied in the European Union Emissions Trading System and less so to the regulation on water, soil and air. The chemicals, oil and gas industries exhibit negative reactions, whereas other polluters (such as construction and materials, and industrial transportation) produce positive abnormal returns.     

Persistence of announcement effects on the intraday volatility of stock returns: Evidence from individual data

We analyze the persistence effects in the empirical relationship between announcement releases and return volatilities of four major companies of the French stock market using high frequency data over the period 1995–1999. Besides its institutional stability, this sample period avoids the econometric difficulties inherent to simultaneous news arrivals. Our approach contributes to the relevant literature in that we focus on individual stock volatilities rather than indices, we distinguish firm‐specific and macroeconomic announcements, and we endogenize both the durations of announcement effects and the response patterns of equity prices. We find that our individual volatilities are affected by a systematic market effect, calendar effects, announcements related to the firms’ macroeconomic environment and announcements related to the firms’ and their competitors’ strategic dealings and commercial outcomes. We find evidence that all volatility responses are gradual with persistence horizons ranging from one to three hours, revealing a significant degree of inefficiency of the French stock market over the period. This inefficiency can be viewed as a breeding ground for the implementation of more performant informational and trading systems that allowed markets to move towards more efficiency.     

Flow and stock effects of large-scale treasury purchases: Evidence on the importance of local supply

The Federal Reserve’s 2009 program to purchase $300 billion of US Treasury securities represented an unprecedented intervention in the Treasury market and provides a natural experiment with the potential to shed light on the price elasticities of Treasuries and theories of supply effects in the term structure. Using security-level data on Treasury prices and quantities during the course of this program, we document a ‘local supply’ effect in the yield curve—yields within a particular maturity sector responded more to changes in the amounts outstanding in that sector than to similar changes in other sectors. We find that this phenomenon was responsible for a persistent downward shift in yields averaging about 30 basis points over the course of the program (the “stock effect”). In addition, except at very long maturities, purchase operations caused an average decline in yields in the sector purchased of 3.5 basis points on the days when those operations occurred (the “flow effect”). The sensitivity of our results to security characteristics generally supports a view of segmentation or imperfect substitution within the Treasury market during this time.     

Characteristics and mechanisms of the U.S. stock market spillover effects on the Chinese A-share market: Evidence from 6 A-share broad-based and 31 sector indices

This study investigated the NYSE and NASDAQ composite indices' return and volatility spillover on 37 Chinese A-share indices. We used data from 2010 to 2022 with Multiplicative-Heteroskedasticity-GARCHX and rolling window analysis. We also applied a vector autoregression and impulse response analysis to study the relationship between the spillover effect and market return or volume condition. We found that: (1) the spillover effect of U.S. stocks can be quickly and mostly absorbed by the A-share market in the next trading day; (2) the dissimilarity of constituents among A-share indices contributes to the differences in the NYSE and NASDAQ spillover effects; (3) the spillover becomes more significant and prominent when the market performance is poor or when some special events occurred.     

Identifying the effects of an exchange rate depreciation on country risk: Evidence from a natural experiment

A natural experiment is used to study exchange rate depreciation and perceived sovereign risk. France suspended coinage of silver in 1876 provoking a significant exogenous depreciation of all silver standard countries versus gold standard currencies like the British pound – the currency in which their debt was payable. The evidence suggests an exchange rate depreciation can significantly increase sovereign risk if a country is exposed to foreign currency debt. We implement a difference-in-differences estimator and find that the average silver country's spread on hard currency debt increased over ten percent relative to non-silver countries.     

A model of returns for the post-credit-crunch reality: hybrid Brownian motion with price feedback

Recent market events have reinvigorated the search for realistic return models that capture greater likelihoods of extreme movements. In this paper we model the medium-term log-return dynamics in a market with both fundamental and technical traders. This is based on a trade arrival model with variable size orders and a general arrival-time distribution. With simplifications we are led in the jump-free case to a local volatility model defined by a hybrid SDE mixing both arithmetic and geometric or CIR Brownian motions, whose solution in the geometric case is given by a class of integrals of exponentials of one Brownian motion against another, in forms considered by Yor and collaborators. The reduction of the hybrid SDE to a single Brownian motion leads to an SDE of the form considered by Nagahara, which is a type of ‘Pearson diffusion’, or, equivalently, a hyperbolic OU SDE. Various dynamics and equilibria are possible depending on the balance of trades. Under mean-reverting circumstances we arrive naturally at an equilibrium fat-tailed return distribution with a Student or Pearson Type~IV form. Under less-restrictive assumptions, richer dynamics are possible, including time-dependent Johnson-SU distributions and bimodal structures. The phenomenon of variance explosion is identified that gives rise to much larger price movements that might have a priori been expected, so that ‘25σ’ events are significantly more probable. We exhibit simple example solutions of the Fokker–Planck equation that shows how such variance explosion can hide beneath a standard Gaussian facade. These are elementary members of an extended class of distributions with a rich and varied structure, capable of describing a wide range of market behaviors. Several approaches to the density function are possible, and an example of the computation of a hyperbolic VaR is given. The model also suggests generalizations of the Bougerol identity. We touch briefly on the extent to which such a model is consistent with the dynamics of a ‘flash-crash’ event, and briefly explore the statistical evidence for our model.