2.1. Liquidity Synchronization
Liquidity synchronization refers to the impact of market-wide liquidity changes on individual stock liquidity. This phenomenon has captured the interest of academicians over the last two decades, who have covered an extensive range of related issues. Although researchers have long been interested in investigating the significant role of liquidity in stock markets, most studies on market microstructures have focused on a single security. Researchers have recently argued that liquidity is not merely an attribute of single security and it encompasses the entire market, which has been coined systematic or liquidity synchronicity (
Chordia et al. 2000;
Huberman and Halka 2001;
Hasbrouck and Seppi 2001;
Rupeika-Apoga and Nedovis 2016;
Choe and Yang 2010). Several studies have documented the presence and dynamics of liquidity synchronicity. Within this context,
Chordia et al. (
2000) conducted the first study on liquidity synchronicity. Their analysis focuses on the impacts of daily fluctuations in industry and market liquidity on the liquidity of a single stock. The results reveal a notable impact of industry and market-wide liquidity on a single firm’s liquidity. Similarly,
Hasbrouck and Seppi (
2001) investigated Dow 30 stock and found a single common component that drives liquidity.
Huberman and Halka (
2001) similarly selected 240 stocks of the NYSE at random from 254 observations to identify the presence of liquidity synchronicity. The author further investigated the role of asymmetric information and inventory risk in liquidity synchronicity. However, no evidence was provided on the impacts of the selected variables on liquidity synchronicity. In a related study,
Wang (
2010) analyzed developed and emerging economies and found that a group of global and regional factors have more significant impacts on liquidity synchronicity than a single factor. The study shows that global factors affect liquidity synchronicity through shocks in volatility and returns, while regional factors affect liquidity synchronicity through shocks in volatility and liquidity.
To gain insight into liquidity co-movement,
Galariotis and Giouvris (
2007) studied the co-movement of liquidity in the United Kingdom during different trade regimes. The London Stock Exchange changed its trade regime for FTSE250 stocks from a quote-driven regime to a hybrid regime and that for FTSE100 stocks from a quote-driven regime to an order-driven regime in the period studied. The study shows that for FTSE250 stocks, liquidity synchronicity is strong for the portfolio level, while for FTSE100 stocks, phenomena are strong not only at the portfolio level but for individual stocks as well. However, overall synchronicity remained similar on average across different trading regimes irrespective of the type of liquidity provision involved.
Huberman and Halka (
2001) similarly identified liquidity synchronicity in NYSE quote-driven markets. The authors conclude that liquidity emerges due to the existence of noise traders in the market. In a related study,
Kempf and Mayston (
2008) analyzed liquidity synchronicity in the Frankfurt Stock Exchange. Since for medium and small trades, the inside spread shows only the systematic risk of liquidity, the authors expanded their study of liquidity synchronicity beyond best prices to identify high levels of trade systematic liquidity risk. They found large stock portfolios to carry much higher levels of systematic liquidity risk than small stock portfolios. Further, systematic liquidity risk is high when markets are falling and in the morning. Similarly,
Fabre and Frino (
2004) studied the presence of liquidity synchronicity in the Australian Stock Exchange (ASX), which is a purely order-driven market. In contrast to earlier research, some evidence of market-wide liquidity synchronicity is found in ASX stock, though with less pervasiveness and significance as that found in other markets. These results conform to the fact that the ASX and other markets of the developed world have different structures. Likewise,
Fernando and Herring (
2003) showed that common shocks of liquidity caused by the recent financial crisis are long-lasting and cannot be diversified. This is the case because, for an order-driven market, negative shocks render liquidity a scarce commodity, as more market players withdraw from the security market due to considerable order imbalances. In investigating the Amman Stock Exchange,
Tayeh (
2016) argued that due to differences in market structures, impacts of market-wide liquidity on individual stock liquidity differ during the pre- and post-automation of a trading system. Generally, the results show varying levels of liquidity commonality on manual and automated trading platforms.
While the focus of the synchronicity literature has been on the equity market, empirical studies have also explored liquidity synchronicity in various other markets. For example,
Friewald et al. (
2012) explored synchronicity in liquidity in the bond market.
Marshall et al. (
2013) studied synchronicity in commodity markets.
Corò et al. (
2013) examined the synchronicity of liquidity in credit swap markets.
Anthony et al. (
2017) studied liquidity synchronicity in secondary corporate markets and found that liquidity synchronicity increases in varied ways during a global financial crisis.
Mancini et al. (
2013) conducted a first systematic study on liquidity synchronicity in foreign exchange markets.
2.2. Determinants of Liquidity Synchronization
Several empirical studies have been conducted across the globe to identify possible causes of liquidity synchronicity. For instance,
Chordia et al. (
2000) identified the cost of inventory and asymmetric information as possible causes of liquidity synchronicity.
Coughenour and Saad (
2004) studied covariation in liquidity among securities traded by a single firm in the quote-driven market. The authors found that shared information and capital among specialists within a firm result in co-movement in their liquidity provisions.
Hameed et al. (
2010) found that market fluctuations affect capacities to fund financial intermediaries and result in covariation in their liquidity provisions.
Domowitz et al. (
2005) found that in an order-driven market, order type correlations act as an economic force that causes liquidity synchronicity.
To investigate, which factors drive liquidity co-movement,
Choe and Yang (
2010) investigated the Korean Stock Exchange to determine the causes of liquidity synchronicity. Inventory costs, investor sentiment, information asymmetry and volatility are studied as potential causes. The empirical analysis shows that higher levels of liquidity synchronicity are caused by information asymmetry, investor sentiments, volatility and style-based trading. However, inventory costs do not have significant effects on liquidity synchronicity. Further, more individual trading is related to more synchronicity in liquidity, which is a sign of strong investor sentiment in the Korean Stock Exchange.
Hillier et al. (
2007) similarly studied the relationship between firm size and liquidity synchronicity. The authors developed a model of spreads and information to provide insight into these factors. Their empirical evidence shows that the interval over which liquidity movements are measured has significant impacts on the presence and magnitude of common variability in liquidity. Such intervals form due to delays in information incorporation into the bid and ask spreads. Similarly,
Hameed et al. (
2010) found that asset market values have an asymmetric impact on liquidity. In line with theoretical models, negative returns reduce liquidity much more than increases in liquidity due to positive returns. Thus, liquidity synchronicity and levels of liquidity are affected by market declines. It has also been found that within an industry, liquidity synchronicity increases to a formidable level when returns on other industries are negative and significant. Likewise,
Brockman et al. (
2009) studied liquidity synchronicity using data from 47 stock exchanges and intraday spreads. The authors found that exchange level changes across world stock exchanges greatly influence firm-level changes in liquidity. The stock exchanges of emerging Asian economies exhibit more synchronicity than stock exchanges in Latin America. After exploring the role of liquidity synchronicity in individual stock exchanges, the researchers examined the phenomenon across exchanges and found that bid-ask depths and spreads affect global sources. Local sources contribute almost 39% of an individual firm’s liquidity synchronicity, while global sources contribute 19% to the overall synchronicity of the same firm. Sources of global synchronicity and exchange levels are also considered by the researchers. It is found that both US macro-economic and domestic statements affect synchronicity.
Brockman and Chung (
2002) studied the Hong Kong Stock Exchange, which is one the world’s largest order-driven markets. They found that liquidity synchronicity includes components from both industries and markets. As opposed to what is found for quote-driven markets, no positive relationship is found between a firm’s size and its sensitivity to variations in market-wide bid-ask spreads. However, market stress has a stronger effect on the synchronicity of large firms than on that of smaller firms.
Liquidity synchronicity can be a result of both demand and supply-side variables.
Koch et al. (
2016) postulated that interrelated trading done by investors for a single stock explains liquidity synchronicity across stocks. From data on stock liquidity and mutual fund ownership in AMEX and NYSE stocks for 1980 to 2008, the authors concluded that mutual funds play an important role in liquidity synchronicity. The results show a correlation between stocks owned by mutual funds experiencing liquidity shocks and stocks with high turnover. Both types of stocks exhibit higher levels of liquidity synchronicity. In a related study,
Wang (
2013) examined the effect of volatility and market returns on liquidity variations in 12 equity markets. The sample used includes both emerging and developed markets. The study shows that common factors significantly impact liquidity variations in equity markets. Furthermore, volatility is found to be the least important factor in determining cross-market average liquidity. Regional factors are found to have effects through volatility and liquidity shocks, and market dynamics within the United Kingdom and the United States are found to have few effects on emerging markets.
Sensoy (
2016) similarly studied Turkey’s stock market to investigate the effects of macroeconomic and monetary policy statements on liquidity synchronicity. The study interestingly finds that only shifts in US macroeconomic and monetary policy cause liquidity synchronicity in the market. Furthermore, there is a significant upward surge in liquidity synchronicity beyond best price quotes, showing that incorrect results on liquidity synchronicity can be obtained when researchers consider spreads at best prices.
Corwin and Lipson (
2011) studied the NYSE and found that liquidity synchronicity levels are relatively lower in large firms than in smaller firms.
Kuo et al. (
2017) explored the Taiwan Stock Exchange to study the tick size impact on liquidity synchronicity. Their results reveal that a small tick size can have a significant impact on market quality and liquidity risk.
Chen et al. (
2013) empirically evaluated the Chinese Stock Market to identify sources of synchronicity that result in liquidity change. The authors studied the interdependence of changes in liquidity synchronicity and the involuntary trading behaviors of institutional investors. Their results show that the involuntary trading behaviors of investors of an open-end fund have reasonable impacts on the liquidity synchronicity of China’s Stock Exchange.
Deng et al. (
2018) also studied 39 stock markets of different countries for 2000–2014 to analyze the relationship between liquidity synchronicity and the institutional ownership of foreign investors. The results reveal an inverse relationship between global foreign institutional ownership and the liquidity synchronicity of stocks. Foreign investors are in a better position to decrease liquidity synchronicity through corporate transparency. US based and independent foreign investors can exercise greater control over the liquidity synchronicity of a stock. Furthermore, there is a U-shaped relationship between the liquidity synchronicity of a stock and foreign institutional relationship. Thus, a foreign institutional investor can substitute a country’s corporate governance level, minimize the effects of local culture, and manage uncertainties of the economic policy. The study also shows that liquidity synchronicity bridges the relationship between firm valuation and foreign institutional ownership. This ownership can increase firm valuation through stock liquidity and its liquidity synchronicity. Similarly,
Gold et al. (
2017) examined liquidity synchronicity in the Canadian Stock Market from 2008 to 2015. The authors found that changes in liquidity are common across the market and more significant in specific industries. They found that industry and market-specific liquidity factors have major effects on individual asset liquidity. Thus, the liquidity of an individual asset is predominantly affected by industry and market-wide liquidity. In a similar study,
Narayan et al. (
2015) evaluated four hypotheses on liquidity synchronicity in Chinese Stock Markets. The authors hypothesize that liquidity changes with firm size, that market-wide liquidity directly affects individual stock liquidity, that there is an asymmetric effect on liquidity synchronicity, and that individual stock liquidity is affected by related sector liquidity. Data on 48 million and 34 million transactions pertaining to the Shenzhen and Shanghai stock exchanges are analyzed. The results show that among the three key sectors studied, the liquidity of the industrial sector provides important evidence for explaining individual stock liquidities. The study also finds evidence of liquidity synchronicity and of strong impacts of industry-wide liquidity on an individual stock’s liquidity. The empirical evidence found does not support the size or asymmetric effects of market liquidity on the liquidity of an individual stock. In a similar work by
Barberis et al. (
2005), it is shown that most investors categorize firms into different groups, while trading resources are allocated among a group of firms rather than to individual firms. The correlated trading behaviors of investors induce the liquidity and return co-movement of stocks.
Pirinsky and Wang (
2006) found a common tendency for investors to assign more weight to local firms while forming portfolios. Correlated trading resulting from this local bias induces liquidity co-movement in the same region.
Green and Hwang (
2009) reported that stock categorization by investors is based on security returns. Price-based preferences encourage price-based synchronicity. The authors found strong patterns of co-movement in stocks with similar prices.
Greenwood (
2008) similarly found that stocks newly added to the index co-vary with increasing intensity relative to existing member stocks.
Kamara et al. (
2008) investigated the common shares of US firms to study liquidity synchronicity for 1963 through 2005. Their findings show that synchronicity significantly amplified for larger firms, while for small firms, the authors found a significant decline in liquidity synchronicity. Considering developments that affected US equity markets in the sampled period, the authors further studied data on the institutional ownership of common equity and found that an increase in institutional ownership is related to an increase in the sensitivity of stocks to systematic liquidity shocks. Index trading and institutional investing are more prevalent among large stocks than small stocks. It is also found that percentage differences in institutional ownership between large and small stocks can better explain variances in their respective liquidity betas. These results suggest that changes in the structures of stock markets cause an increase in large stocks’ exposure to liquidity synchronicity.
Karolyi et al. (
2012) studied behaviors of liquidity synchronicity across countries over time while considering demand determinants such as correlated the trading behaviors of institutional and international investors, investor sentiment, incentives available for investment in stocks and supply determinants such as liquidity available to financial intermediaries for funding. The study finds higher levels of liquidity synchronicity in countries with more market volatility, significant proportions of foreign investors and higher levels of correlated trading.
Brunnermeier and Pedersen (
2009) similarly found that high levels of market volatility and sharp declines in the market significantly impact liquidity available to financial intermediaries. As a result, liquidity in the market is reduced, and synchronicity in liquidity is increased.
Kamara et al. (
2008) and
Koch et al. (
2016) found that the correlated trading behaviors of investors from institutions can increase liquidity synchronicity. Furthermore, liquidity synchronicity can arise when demand for liquidity across stocks is correlated. This happens when individual investors cannot identify better incentives to trade in individual stocks.
Morck et al. (
2000) found a correlation between such incentives and regulations on transparency and investor protection and showed that investor sentiment also affects liquidity synchronicity. Similarly,
Bouchaddekh and Bouri (
2015) studied the Tunisian financial market from 2011 to 2013. Variables empirically studied include the number of transactions, volatility, access to new information, trading volumes, etc. The researchers found that the return, volume and arrival of new information have strong effects on liquidity synchronicity.
Watanabe and Watanabe (
2008) found that macroeconomic factors affect the liquidity of the stock market in times of volatility.
Chordia et al. (
2008) explained that in response to expansionary monetary policy, the liquidity of the stock market increases. It is further elaborated that macroeconomic shocks indirectly affect market returns, liquidity and turnover.
Jensen and Moorman (
2010) and
Lu-Andrews and Glascock (
2010) analyzed causes of time variations in liquidity premiums in the United States Stock Exchange. These studies reveal that expansionary monetary policy reduces the price of liquidity and that during an economic recession, investors demand a better return for holding illiquid stocks.
Shyu (
2017) examined whether marking to market disclosure affects synchronicity in liquidity in the Chinese Stock Market. The study explores the effect of fair value disclosure on the stock market and its relation to financial crisis. The author studied the relationship between liquidity synchronicity and fair value disclosure by examining how fair value measurement contributes to liquidity synchronicity in the Chinese stock market. Synchronicity in liquidity is a form of systematic risk for individual stocks. Therefore, unexpected liquidity demand will cause stock prices to drop rapidly, while investors holding the same stocks must dispose of their security due to the same liquidity problem. As a result, there is a cyclical drop in market price and an overall decline in systematic liquidity in the financial system.
Lin (
2010) examined the impact of financial market liberalization on liquidity synchronicity in emerging economies. For a sample of 20 emerging economies covering a period of 20 years, it is found that opening local markets to foreign investors increases the liquidity of local markets by limiting asymmetric information. However, financial liberalization also introduces more liquidity risk in the form of liquidity synchronicity. A further investigation shows that higher levels of liquidity synchronicity arise from an increase in inventory risk due to financial liberalization.
Alhassan and Naka (
2017), using daily and annual data for 1995 to 2015 for 50 countries in East Asia and the Pacific region, investigated how oil markets impact liquidity synchronicity. Two transmitting channels are found: oil price returns and volatility effects on liquidity synchronicity. The study reveals that oil volatility and returns explain liquidity synchronicity in countries where there is more integration with oil markets. The authors also found that the effect of oil volatility is more evident in oil-exporting countries than in oil-importing countries. Their findings suggest that oil price volatility in liquidity synchronicity is more substantial for oil sensitive countries than oil price returns except for five OPEC members, where synchronicity in liquidity is heavily affected by oil volatility along with returns. In a similar study,
Tissaoui et al. (
2018) explore synchronicity in liquidity using data from 105 stocks for 2008 to 2014 for the Saudi stock market. The analysis shows strong liquidity synchronicity in the Tadawul stock market and significant synchronicity in liquidity under normal conditions. The study documents that liquidity synchronicity in the Saudi stock market is stronger under different stock market conditions than under different oil market conditions. In exploring the magnitude of this impact, a time-series analysis reveals that liquidity synchronicity is vital across all size-based quartiles, through the magnitude of corresponding impacts varies. Firms with less market capitalization are more vulnerable to synchronicity in liquidity, while those with considerable market capitalization are the least susceptible to synchronicity in liquidity. However, under boom and bust conditions of the oil market, the results are different, where the quartile of small market capitalization is generally the least sensitive to market-wide liquidity, while the second quartile is more susceptible to synchronicity in liquidity.
Pan et al. (
2015) studied the Shanghai Stock Exchange to measure the impacts of investors’ trading activities on liquidity co-movements and common returns. The authors divided their population into retail and institutional investors. Their results reveal that retail traders contribute much less to synchronicity in liquidity than institutional traders. However, retail investors make more substantial contributions to return co-movements. Such contributions are more visible in firms with high levels of information asymmetry. In a related study,
Dang et al. (
2015) explored the impact of international cross-listing on liquidity synchronicity. A large dataset covering more than 20,000 firms and 39 markets for 1996 to 2007 is studied. Their results suggest that the impact of aggregate liquidity shocks is reduced for stocks that have been cross-listed. It is also found that for countries with poor institutional infrastructure, opaque information conditions and high levels of market segmentation, cross-listing has a negative effect on home liquidity synchronicity. In another study,
Isshaq and Faff (
2016) investigated the relationship between liquidity synchronicity and uncertainty in firm fundamentals. Volatility in operating profits is used to measure fundamental uncertainty. The authors argue that liquidity synchronicity is stronger for firms with less volatility in profitability; supporting the prediction that liquidity synchronicity is negatively associated with operating profitability volatility.