Circuit Breakers and Market Volatility: A Theoretical Perspective

This paper examines ex ante effects of circuit breakers (mandated trading halts). We show that circuit breakers, by causing agents to suboptimally advance trades in time, may have the perverse effect of increasing price variability and exacerbating price movements. We next consider a situation in which a circuit breaker causes trading to be halted in both a dominant (more liquid) and a satellite market. As agents switch from the dominant market to the satellite market, price variability and market liquidity decline on the dominant market and increase on the satellite market.     

What Makes Circuit Breakers Attractive to Financial Markets? A Survey

After the stock market crash of October 1987, the Brady Report (1988) and several academic researchers suggested the imposition of "circuit breakers" to prevent the market from fluctuating excessively. Most financial markets in the world have imposed circuit breaker systems, in the form of price limits and trading halts, in an attempt to reduce excessive market volatility. Similar to any other regulations, circuit breakers have proponents and opponents. In this survey, we analyze the benefits and costs of each type of circuit breaker, provide existing theoretical models and predictions related to each type of circuit breaker, and present findings from empirical studies to justify or disqualify the existence of circuit breakers. In addition, we synthesize existing studies and offer directions for further research in this area.     

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.     

Circuit Breakers with Uncertainty about the Presence of Informed Agents: I Know What You Know … I Think

This study conducts experimental asset markets to examine the effects of circuit breaker rules on market behavior when agents are uncertain about the presence of private information. Our results unequivocally indicate that circuit breakers fail to temper unwarranted price movements in periods without private information. Agents appear to mistakenly infer that others possess private information, causing price to move away from fundamental value. Allocative efficiencies in our markets are high across all regimes. Circuit breakers perform no useful function in our experimental asset markets.     

The effectiveness of competing regulatory regimes and the switching effects: Evidence from an emerging market

I investigate the effectiveness of two competing regulatory regimes and the effect of switching from strict price limits to circuit breakers on volatility spillover, and also on trading interference hypotheses. I find that switching to the circuit breakers' regime increases volatility and disrupts the price discovery mechanism. Stock prices are prevented from reaching their equilibrium levels and traders are unable to obtain their desired positions on limits hit day. Moreover, I find that volatility is spread out over the following 2 days post-limit hits within the strict price limits regime. Finally, the results show that price limits interfere with trading activity and affect investors' beliefs and liquidity positions.     

What happened to liquidity when world war I shut the NYSE?

This paper examines how financial markets responded to the longest circuit breaker in American financial history: the four-month suspension of trading on the New York Stock Exchange following the outbreak of World War I. The suspension that began on July 31, 1914 fostered a substitute trading forum called the New Street market. Trading on New Street began almost immediately and offered economically meaningful liquidity services despite its impaired price transparency. A simple cross-sectional model of bid–ask spreads on New Street demonstrates that New Street liquidity responded to economic incentives. New Street's success implies that, from a public policy perspective, expensive back-up trading facilities are not required to preserve liquidity during a trading suspension in established markets. Back-up records of share ownership and transfer facilities, however, are crucial to maintaining liquidity.     

Brokered versus dealer markets: Impact of proprietary trading with transaction fees

In this study, we consider a one-period financial market with a dealer/broker and an infinite number of investors. While the dealer who trades on his own account (with proprietary trading) simultaneously sets both the transaction fee and the asset price, the broker who brings investors' orders to the market (with no proprietary trading) sets only the transaction fee, given that the price is determined according to the market-clearing condition among investors. We analyze the impact of proprietary trading on the asset price, transaction fee, trading volume, and the welfare of investors. We find that the bid and ask prices set by the dealer who can engage in proprietary trading are more favorable to average investors. As a result, both the trading volume and the transaction fee increase, and social welfare improves.     

从光大“乌龙指”事件看高频交易监管

随着电子化交易的发展,高频交易在证券市场中的运用越来越多。高频交易在增加流动性的同时,也因技术故障等问题造成证券市场价格剧烈动荡,这引发了人们的争论,即是否需要对高频交易进行限制。高频交易虽然带来了流动性,但是技术故障引发市场波动,量化交易的助涨助跌,更是会引发崩盘的系统性风险。因此,限制高频交易具有正当性。光大"乌龙指"事件,是我国首例因为技术故障引发的极端事件,应该借此机会反思,建立熔断机制、异常交易的处理规则和法律制度。     

Do regulatory policies affect the flow of information in emerging markets?

In a previous paper we established that volatility is best explained by contemporaneous rather than lagged trading volume in the Egyptian stock exchange (EGX). The main objective of this paper is to investigate the effects of regulatory policies - namely the switch from price limit to circuit breaker - on the dynamic relationship between trading volume and stock returns volatility in the EGX. Using daily returns data for 20 actively traded companies as well as the EGX30 market index, the Generalised Method of Moments (GMM), results show that the volume-volatility relationship is not only endogenous but is also structurally altered by the switch.     

Opening price manipulation and its value influences

We investigate how opening price manipulation influences market behaviors and investors' returns. Analyzing direct evidence comprising 87 opening price manipulation cases, and indirect evidence consisting of 19,003 suspected cases detected by an opening price manipulation identification model that we construct, we examine the impact of manipulation on mispricing, investors' welfare, trading activity and price volatility. Our results indicate that manipulated stocks experience significantly lower returns and a higher probability of price reversal after manipulation. Investors who purchase manipulated stocks at their opening price, or the volume-weighted average price, on the manipulation day make losses on their investments. Further, manipulation increases market trading activity and price volatility due to the influx of retail investors. Our additional analysis demonstrates that enhancing the intensity of external supervision and internal governance can mitigate mispricing caused by opening price manipulation. Our study provides novel evidence of the economic consequences of open market manipulation and policy implications for governments and regulators to develop effective supervisory processes to reduce manipulation and mitigate its impact on efficient markets.     

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.     

Costly Information Acquisition,Social Networks,and Asset Prices: Experimental Evidence

We design an experiment to study the implications of information networks for incentives to acquire costly information, market liquidity, investors' earnings, and asset price characteristics in a financial market. Social communication crowds out information production as a result of an agent's temptation to free ride on the signals purchased by her neighbors. Although information exchange among traders increases trading volume, improves liquidity, and enhances the ability of asset prices to reflect the available information in the market, it fails to improve price informativeness. Net earnings and social welfare are higher with information sharing due to reduced acquisition of costly signals.     

Information‐Hedging Disclosures and Insider Trading

I model the effect of disclosure on the tradeoff between information risk, liquidity risk, and price risk for a well‐informed, risk‐averse insider. Revealing some information before trading decreases the variability of the insider's information advantage and thus reduces his information risk. Disclosure also lowers adverse selection costs for market makers, which reduces the insider's liquidity risk by increasing his trading flexibility. However, disclosure increases price risk for the insider because the price fully reflects the revealed information. The reduction in information and liquidity risks outweigh the rise in price risk when the insider is less risk averse because a less risk‐averse insider's information‐based motive for trading is stronger than his hedging motive. The opposite relation holds when the insider is more risk averse. Therefore, a less (more) risk‐averse insider experiences an increase (decrease) in welfare when he discloses some information before trading. Cost of capital and policy implications are identified.     

A theory of the transition to secondary market trading of IPOs

We develop a model in which investment banks and institutional investors collaborate in smoothing an initial public offering's (IPOs) transition to secondary market trading. Their intervention promotes welfare under the assumption that significant new information arrives in the market in the immediate aftermath of the IPO. Under this assumption, it is optimal to stage the offering and suboptimal to commit to selling shares at a uniform price. The optimal strategy yields an economic rationale for secondary market price stabilization for IPOs carried out via a well-coordinated network of repeat institutional investors.     

Stock Market Crashes and the Performance of Circuit Breakers: Empirical Evidence

This study examines the behavior of a small stock market with circuit breakers and with a one-hour preauction order imbalance disclosure, during the October 1987 crash. The crash and its aftershocks lasted for a week and selling pressure was concentrated in higher beta, larger capitalization, and lower leverage firm stocks. Circuit breakers when implemented reduced the next-day opening order imbalance and the initial price loss; however, they had no effect on the long-run response. Some price overreaction and reversal phenomena also are documented.     

Price volatility,welfare, and trading hours in asset markets

This paper studies the consequences of opening asset markets more often for the properties of asset prices and social welfare. For all reasonable parameter values, increasing trading hours lowers average asset prices, increases unconditional asset price volatility at a given point in time, and decreases unconditional asset price volatility when averaged over the period of time that includes the additional hours that markets are open. Unconditional social welfare is increased by opening markets more often, although the welfare gains are small – well below 1% of lifetime consumption. In contrast, because expanding hours of trading affects agents' information sets, the welfare effect of more trading hours conditional on information available to agents can be large and the effect can be negative.     

On Speculation, Index Futures Markets, and the Link Between Market Volatility and Investor Welfare

This paper develops a trading model that incorporates informed speculators as well as investors who possess incorrect expectations about asset values. It is shown that the introduction of an index futures market, by stimulating additional misinformed speculation, increases market liquidity and adversely affects price variability and efficiency in the underlying stock markets. An analysis of the welfare of uninformed hedgers suggests that the relationship between uninformed investor welfare and two key parameters that dominate policy discussions, market liquidity and price variability, is quite tenuous.     

Circuit Breakers and the Tail Index of Equity Returns

Using the tail index of returns on U.S. equities as a summarymeasure of extreme behavior, we examine changes in the equitymarkets surrounding the development of program trading for portfolioinsurance, the crash of 1987, and the subsequent introductionof circuit breakers and other changes in market architecture.Recently-developed tests for the null of constancy of the tailindex, versus the alternative of a change at an unknown date,permit inference on changes in extreme behavior over a longtime period while allowing for second-moment dependence in thereturn data. We find strong evidence of a decrease in the tailindex (increase in the probability of extreme events) aroundthe beginning of large-scale program trading, and weaker, butstill substantial, evidence of further significant change inthe tail index following the introduction of circuit breakers.Point estimates of the tail index suggest that the tail indexmay have roughly regained pre-program trading levels. More generally,the results tend to suggest that long samples of U.S. equityreturns should not be treated as samples from a single distributionfunction, particularly in examining extremes.     

Institutional investor’ proportions and inactive trading

We focus on a typical market anomaly-inactive trading: trading volume shrinks while stock price abnormally jumps. We calibrate a theoretical model with variance ambiguity heterogeneous among investors and illustrate that ambiguity averse investors' proportions enhance trading volume shrinkage and abnormal price jumps. We provide a cross-section analysis of stocks' inactive trading by introducing institutional investors' proportions to measure investor structures' differences among stocks. We also empirically measure relative inactive trading for constituent stocks in S&P 500 from 2014 to 2019 and demonstrate that institutional investors' proportion is negatively related to inactive trading. Finally, we demonstrate that higher proportions of institutional investors lead to less inactive trading anomalies.     

Relationship Trading in Over-the-Counter Markets

We examine the network of trading relationships between insurers and dealers in the over-the-counter (OTC) corporate bond market. Regulatory data show that one-third of insurers use a single dealer, whereas other insurers have large dealer networks. Execution prices are nonmonotone in network size, initially declining with more dealers but increasing once networks exceed 20 dealers. A model of decentralized trade in which insurers trade off the benefits of repeat business and faster execution quantitatively fits the distribution of insurers' network size and explains the price–network size relationship. Counterfactual analysis shows that regulations to unbundle trade and nontrade services can decrease welfare.