Margins and Price Limits in Taiwan's Stock Index Futures Market

This study extends the framework of Brennan (1986) to find the cost-minimizing combination of spot limits, futures limits, and margins for stock and index futures in the Taiwan market. Our empirical results show that the cost-minimization combination of margins, spot price limits, and futures price limits is 7 percent, 6 percent, and 6 percent, respectively, when the index level is less than 7,000. When the index level ranges from 7,000 to 9,000, the efficient futures contract calls for a combination of 6.5 percent, 5 percent, and 6 percent. The optimal margin, reneging probability, and corresponding contract cost are less than those without price limits. Price limits may partially substitute for margin requirements in ensuring contract performance, with a default risk lower than the 0.3 percent rate that is accepted by the Taiwan Futures Exchange. On the other hand, though imposing equal price limits of 7 percent on both the spot and futures markets does not coincide with the efficient contract design, it does have a lower contract cost and margin requirement (7.75 percent) than that without imposing price limits (8.25 percent).     

A note on price limit performance: The case of illiquid stocks

In the Chinese stock markets, there are A-shares and B-shares. Both share-types have identical cash flow rights but different ownership structures (i.e., A-shares are owned by local Chinese citizens and B-shares are owned primarily by foreigners), causing B-shares to be less liquid relative to A-shares. However, even though B-shares have much wider bid—ask spreads than A-shares, both share-types are subject to the same 10% daily price limit regulation. As such, B-shares, simply due to their wider spreads, may be more inclined than A-shares to hit price limits. Our empirical results support this contention. The findings have policy implications. First, given wide spreads for illiquid stocks, exchanges may consider using midpoint prices (between bid and ask prices) to establish price limit ranges for illiquid stocks. In addition, and perhaps more importantly, exchanges may consider using wider price limits for less liquid classes of stocks.     

Price limits in futures markets: effects on the price discovery process and volatility

Price limits are actively employed by many futures exchanges as a regulatory mechanism directed at reducing volatility and improving price discovery process. The aim of this paper is to investigate whether price limits achieve these goals without affecting market liquidity for a number of agricultural futures contracts. We employ models of changing volatility in order to show that price limits do not appear to significantly reduce market volatility. In addition, we find evidence confirming the hypothesis that price limits delay price discovery instead of facilitating it. Our results also suggest that the impact of price limits on volatility and price reversals, found in previous studies, are mainly due to the properties inherent to the futures returns, such as volatility clustering. Finally, although trading decreases significantly due to the price limits, traders do not seem to switch from the contracts affected by price limits to other maturities in order to minimize the impact of circuit breakers.     

Price limit performance: evidence from transactions data and the limit order book

In recent years, organized stock exchanges with daily price limits adopted wider limits as narrower limits were criticized for jeopardizing market efficiency. This study examines the impact of a wide price limit on price discovery processes, using data from the Kuala Lumpur Stock Exchange. Specifically, examined is the impact of daily price limits on (i) information asymmetry; (ii) arrival rates of informed traders; and (iii) order imbalance. Using both trade-to-trade transaction data and the limit order book, we compile evidence that price limits do not improve information asymmetry, delays the arrival of informed traders, and exacerbates order imbalance. These results suggest that price limits on individual securities do not improve price discovery processes but impose serious costs even when the limit band is as wide as 30%.     

Aberrant investor participation amid substantial price swings: high-frequency evidence of magnet-repellent effect from Malaysia

Price limits have skirted controversy since inception. Regulators claim limits curb volatility, allay stressed markets, and encourage reflection on information to trade rationally. Opponents contend saying limits delay the inevitable by postponing volatility, deferring equilibrium price discovery, and obtrude investors’ trading plans. While these undesired effects are all ex-post in nature, some argue that limits – by very existence – threaten to invite trading activities towards themselves and govern trade-flow such that the limit’s prophecy is fulfilled. This is known as magnet effect. Theoretical development of this ex-ante effect has been in hibernation since the 1990s. Thus, empirical attempts have been made to test its existence – mostly in East-Asian exchanges with tight limits. Bursa Malaysia, however, defends its ±30% limit for ~30 years based on internal (unpublished) studies. This paper employs a battery of tests to examine the existence and magnitude of magnet effect and – its counterpart – repellent effect in Malaysia. Our findings suggest a weak form of magnet effect and comparable degrees of repellent effect. Moreover, we report price acceleration beyond a threshold point unsupported by order aggression or volume support necessary to constitute a magnet effect. We discuss policy import of our findings and recommend future research avenues worthy of pursuit. Price limits’ opponents argue that limits can threaten to invite trading activities towards themselves such that the limit’s prophecy is fulfilled. Existence of this phenomenon—the magnet effect—has been tested mostly in exchanges with tight limits. This paper employs a battery of tests to examine the existence and magnitude of magnet effect in Bursa Malaysia, which employs a wide price limit. Our findings suggest a weak form of magnet effect and comparable degrees of repellent effect. Moreover, we report price acceleration beyond a threshold point unsupported by order aggression or volume support necessary to constitute magnet effect.     

Setting the futures margin with price limits: the case for single-stock futures

Price limits are artificial boundaries established by regulators to establish the maximum price movement permitted in a single day. We propose using a new censoring method that incorporates the effect of price limits on the futures price distribution and investigates how to set an appropriate daily margin level using single-stock futures in Taiwan. We compare our estimations with those obtained using the method in Longin (J Bus 69:383–408, 1999). The results show that (1) the margin levels derived from the Longin method, which ignore price limits in the estimation, are lower than those in our censoring method; and (2) the legal margin for single-stock futures set at 13.5 % by the Taiwan Futures Exchange to avoid default risk appears to be too high.     

Optimal clearing margin,capital and price limits for futures clearinghouses

We provide a model for a futures clearinghouse to use for setting optimal levels of clearing margin, capital and price limits, which minimizes the costs to clearing firms and simultaneously protects the clearinghouse from default by clearing firms. We show how to estimate the capital requirement, which supports the clearinghouse’s residual default risk that is not covered by the clearing margin. We apply our model to the Winnipeg Commodity Exchange and demonstrate that price limits reduce the sum of optimal clearing margin and capital to a level that is substantially lower than that required in the absence of price limits.     

How do risk attitudes of clearing firms matter for managing default exposure in futures markets?

This article proposes a theoretical framework that is built upon extreme value theory to study three instruments (i.e. margin, capital requirement and price limits) for managing default risk in futures markets. Specifically, the exceedances over a price threshold are modeled using a generalized Pareto distribution, and the models are static (one-period). We incorporate the risk attitudes of clearing firms into the framework to investigate the efficacy of these instruments under several risk measures, including value-at-risk measures, expected-shortfall measures and spectral risk measures. An empirical study on the VIX futures (or VX) data shows that the effectiveness of these market instruments rests not only on clearing firms' risk attitudes, but also on the tail fatness of the futures price distribution. Moreover, the shift in the risk attitudes of clearing firms may cause interactions among these instruments, which casts new light on the economic rationale of price limits.     

Price limit bands,asymmetric volatility and stock market anomalies: Evidence from emerging markets

I investigate the effects of imposing different bands of price limits on stock returns and volatility in the Egyptian (EGX), Thai (SET) and Korean (KRX) stock exchanges. In addition, the paper examines whether the switch from narrow price limits (NPL) to wider price limits (WPL) structurally alters volatility and the day of the week anomaly. Using the extended EGARCH and PARCH asymmetric volatility models, I found that the switch from NPL to WPL structurally altered both asymmetric volatility and the day of the week anomaly in the EGX, SET and KRX. I argue that the price discovery mechanism is disrupted due to the switch as closing prices do not fully reflect all information arrived in the market when prices hit the limits and that is reflected on volatility and market efficiency.     

融资融券对个股交易变化影响的实证研究

文章运用融资融券155只标的证券的截面数据,实证研究了融资融券对个股交易变化的影响.结果发现,融资融券余额对标的股的个股回报率、交易股数、率都具有较为显著的正向作用,分析了导致这一现象出现的原因,并针对如何充分发挥融资融券价格发现功能,平抑股价过度波动提出了相关政策建议.     

Risk aversion and price limits in futures markets

Assuming that a representative trader is risk-neutral, Brennan [1986. Journal of Financial Economics 16, 213–233] shows that price limits, in conjunction with margins, may help reduce the default risk, lower the margin requirement, and decrease the total contract cost. We show that Brennan's result is true only when the trader's degree of risk aversion is low and the precision of additional information about the equilibrium futures price is also low. When the trader either is more risk-averse or can receive precise information, price limits become ineffective in either reducing the default probability, cutting down the margin requirement, or lowering the contract cost.     

SWITCHING TO A TEMPORARY CALL AUCTION IN TIMES OF HIGH UNCERTAINTY

We evaluate a stock-specific circuit breaker implemented in several European stock exchanges, which consists of a short-lived call auction triggered by intraday stock-specific price limits. It differs from U.S. trading halts in that it is short-lived and nondiscretionary, and a trading mechanism (continuous or discrete) is always going. It differs from daily price limits in that trade prices are not restricted once the limit is hit. Intraday price ranges are smaller and adjusted to the recent volatility, so that limit hits are more frequent. We contribute to the debate about circuit breakers by enlarging the span of these mechanisms studied.     

Why Do Price Limits Exist in Stock Markets? A Manipulation‐Based Explanation

Numerous stock market regulators around the world impose daily price limits on individual stock price movements. We derive a simple model that shows that price limits may deter stock market manipulators. Based on our model's implications, we predict that regulators impose price limit rules for markets where the likelihood of manipulation is high. We present empirical evidence consistent with this hypothesis. Our study is the first to formally propose a manipulation‐based rationale for the existence of price limits in stock markets.     

投资者关注与市场反应——来自中国证券交易所交易公开信息的自然实验

涨停的股票能否被交易公开信息披露取决于收益率排名中的随机因素,与股票的基本面特征无关。本文利用这一机制设计自然实验检验了投资者关注对股价的影响。实证结果显示交易公开信息披露使股票受到投资者更多的关注,增加了小额资金的净流入,减少了大额资金的净流入和股价的短期收益率,抑制了股价短期波动率,同时降低了股价在长期发生反转的可能性。频繁登上交易公开信息的知名营业部买入的股票受到更多关注,相应的市场反应也更加显著。进一步的研究表明监管性信息披露引发的投资者关注通过降低市场信息不对称抑制了股价反转。     

Which Price is Right: Load or Premium?

This paper uses national time series data for the United States to investigate whether changes in the premium or loading fee offer a better explanation for variations in the percentage of the population with private health insurance from 1960 to 2004. The empirical results suggest that premium provides a better measure of price when estimating the demand for health insurance at the extensive margin. The empirical analysis also indicates that the aggregate short-run price and income elasticities of demand for health insurance are fairly close at ?0.19 and 0.27, respectively. One implication is that the percentage of the population with private health insurance in the United States should continue to decline in the future if real premiums persistently grow significantly faster than the overall economy.     

融资融券能否提高交易所自律监管效率?

本文利用沪深300指数日收益率为样本,采用GARCH-M模型、EGARCH-M模型分析融资融券业务推出对我国股市波动性的影响,并以波动性为交易所自律监管效率的代理变量来进一步说明融资融券能否提高我国交易所自律监管的效率。结果表明:融资融券业务从试点推出到转为常规业务的一年半以来,我国股市的波动性有所减小,波动的杠杆效应减弱,表明融资融券能起到稳定市场的作用。同时也说明了金融创新工具推出和应用的市场化改革能够促进我国交易所自律监管功能的发挥。     

A股、H股新股初始收益率比较研究

本文借鉴IPO已有的研究成果，分别对上海A股、香港H股的新股初始收益率进行了实证研究，探讨了企业选择A股或H股发行上市所导致的两个市场的不同反应及其真正动因。实证结果表明，上海A股市场较香港H股市场具有更高的新股初始收益率，但呈逐年递减趋势；A股市场的新股初始收益率与中签率、发行价、上市首日开盘价、上市首日换手率显著相关，而H股市场的新股初始收益率则与净利润增长率、香港恒生指数显著相关。     

FURTHER EXAMINATION OF PRICE DISCOVERY ON THE NYSE AND REGIONAL EXCHANGES

I re‐examine price discovery on the New York Stock Exchange (NYSE) and regional exchanges. I employ three common‐trend cointegration models to analyze the equilibrium dynamics between the NYSE and regional exchanges for the thirty Dow stocks. The overall results show that whether the regional exchanges free‐ride on the NYSE in obtaining equilibrium prices depends on whether trade prices or quotes are examined. The regional exchanges play a significant (though less important) role in the price‐discovery process for trade prices. However, the contributions of regional exchanges in price discovery of quotes are negligible. I explain the inconsistency between the results using quotes and those using trades. I also highlight the problems of using either quotes or trades in examining this free‐riding hypothesis and suggest future research on the different informativeness of trades on the NYSE and regional exchanges. JEL classification: G20, C32.     

The effect of price limits on intraday volatility and information asymmetry

We investigate the effect of price limits on intra-day volatility and information asymmetry using transactions data from the Taiwan Stock Exchange. Proponents of price limits argue that they provide an opportunity for investors to reevaluate market information and make more rational trading decisions. We identify three different limit hits – closing, single, and consecutive – and hypothesize that only the consecutive limit hits are likely to provide such an opportunity, namely, to counter investor overreaction (volatility hypothesis) and to enhance information revelation (information asymmetry hypothesis). Our empirical evidence supports the volatility hypothesis. Our findings generate important policy implications for stock markets that have price limits.     

竞争是否缓解了商业银行风险承担？ ——基于利率市场化视角下的GMM检验

本文选取2005-2018年34家沪深上市银行的年度面板数据,通过GMM面板回归和DID双重差分模型实证分析了利率市场化视角下价格竞争和市场竞争对银行风险承担水平的影响。实证分析结果显示,利率市场化下的利差收窄提升了商业银行风险抵御能力,破产风险和概率有所下降;价格竞争和市场竞争使得商业银行“以量补价”的信贷投放冲动较强,加剧了信用风险;在利率市场化进程下,商业银行面临的价格竞争和市场竞争使得自身风险承担水平受到了更大冲击。