Decimals And Liquidity: A Study Of The Nyse

Using a carefully constructed matched sample of control (nondecimal) stocks, we isolate the effects of decimalization for a sample of NYSE‐listed common stocks trading in decimals. We find that the quoted depth as well as the quoted and effective bid‐ask spreads declined significantly following decimalization. Additionally, both the number of trades and trading volume declined significantly. Stock return volatilities display an initial increase but a decline over the longer term, probably as traders become more comfortable in their new milieu.     

An evolutionary multi‐objective optimization of trading rules in call markets

We evaluate an agent‐based model featuring near‐zero‐intelligence traders operating in a call market with a wide range of trading rules governing the determination of prices and which orders are executed, as well as a range of parameters regarding market intervention by market makers and the presence of informed traders. We optimize these trading rules using a multi‐objective population‐based incremental learning algorithm seeking to maximize the trading volume and minimize the bid–ask spread. Our results suggest that markets should choose a small tick size if concerns about the bid–ask spread are dominating and a large tick size if maximizing trading volume is the main aim. We also find that unless concerns about trading volume dominate, time priority is the optimal priority rule. Copyright © 2011 John Wiley & Sons, Ltd.     

THE EFFECTS OF DECIMALIZATION ON RETURN VOLATILITY COMPONENTS,SERIAL CORRELATION,AND TRADING COSTS

We examine the composition of return volatility, serial correlation, and trading costs before and after decimalization on the New York Stock Exchange. We decompose the variance of price changes into components associated with public news, rounding errors, and market‐making frictions. We find that when stocks move from a fractional to a decimal trading system, the variance components due to market‐making frictions and rounding errors decline significantly, whereas the component due to public news remains unchanged. The serial correlation of price changes weakens substantially after decimalization. The uninformed component of bid‐ask spreads decreases significantly whereas the informed component has no significant change.     

Index Options-Futures Arbitrage: A Comparative Study with Bid/Ask and Transaction Data

We can infer from bid/ask quotations and transaction prices that where options contracts are traded under a competitive open‐outcry market‐making system, the options and futures markets are dynamically efficient. Ex‐ante analysis shows that potential arbitrage opportunities disappear within five minutes. Transaction price data understate both the frequency and magnitude of arbitrage opportunities that are signaled by bid/ask quotes. Quotes stale fast, so opportunities are short‐lived and some of the arbitrage opportunities are deceptive. Nonetheless, the evidence suggests that bid/ask quotes provide valuable trading signals to arbitrageurs. Profitability from exploiting the quotes is negatively related to execution delay and execution risk.     

Explaining Monday Returns

The Monday effect is reexamined using two stock indexes and a sample of 452 individual stocks that trade on the London Stock Exchange. The results based on conventional test methods reveal a negative average return on Monday. Extending the analysis to examine the effects of various possible influences simultaneously, the average Monday return becomes positive and does not differ significantly from the average returns of most other days of the week. Fortnight, ex‐dividend day, account period, (bad) news flow, trading activity, and bid‐ask spread effects are all controlled for. The results broadly support the trading time hypothesis.     

Market Response to Liquidity Improvements: Evidence from Exchange Listings

The study examines a sample of 895 stocks that moved from Nasdaq to the New York Stock Exchange or to the American Stock Exchange (Amex) between 1971 and 1994. We show how various measures of liquidity such as the bid‐ask spread, trading volume, and stock price precision improve in somewhat different ways upon transfer to NYSE (Amex). We also find that reductions in trading costs (percentage spread) and in pricing error volatility (Hasbrouck's σ₅) can explain most of stock market's positive response to exchange listing. Thus, liquidity has many facets and cannot be represented by the bid‐ask spread alone.     

The Declining Role of NASDAQ Market Makers

We compare the liquidity providing behavior of NASDAQ market makers in 2010 to their behavior in 2004. We examine how frequently market makers are at the inside quote, what market and stock specific factors influence market makers’ behavior, and the relation between market maker participation and intraday bid‐ask spread patterns. We observe a decrease in the percent of the trading day dealers’ quote at the inside, a decline in the number of market makers, and a decrease in the influence market makers have on intraday spread patterns. The results suggest that the role of NASDAQ market makers declines over time.     

Microstructure and reverse stock splits

In this paper we show that, similar to NYSE/AMEX stocks, NASDAQ stocks exhibit significant ex date returns for reverse stock splits. Although the 10-day cumulative return after the ex date is close to –10%, this does not violate market efficiency, because the average bid-ask spread for the reverse split stock is at least double this return. We also document that these large negative returns are mostly due to a drop in the ask price while bid prices barely change at all. Furthermore, the ex date returns are negatively related to trading volume.These results suggest that there is abnormal selling and a significant buildup of market makers' inventories near the ex date. To reduce the inventory buildup, market makers lower ask prices to induce buying by investors, resulting in the observed negative returns. Lowering bid prices, an alternative strategy for reducing inventories, is not attractive to market makers due to competitive factors and the reduction of commissions associated with a smaller number of transactions. Notably, selling investors have no incentives to sell their stocks early to avoid the observed negative ex date return, since this return is largely an ask price phenomenon and does not represent realized returns to sellers.     

A new methodology for studying intraday dynamics of Nikkei index futures using Markov chains

The empirical study of intraday patterns of stock trading volatilities and bid–ask spreads in the literature depends on assumptions of specific price generating process and may therefore not be robust to distributional assumptions. By creating discrete states that conform more naturally to the way prices are actually quoted in the derivatives and assets markets, we employ a new methodology of Markov chains for studying the intraday dynamics of derivative prices. We apply the method to study the intraday behavior of the Nikkei index futures prices, trading volumes, and spreads. We find some interesting results such as higher probabilities of transitions between larger volatilities at the opening and closing times. The volatility at lunch break is strikingly low. Contrary to most of the literature, the Nikkei intraday bid–ask spread does not show a U-shaped pattern. We offer some explanations.     

DAY‐END EFFECT ON THE PARIS BOURSE

We study the day‐end effect on the Paris Bourse, a computerized order‐driven market with competing dealers. The day‐end return is approximately double the magnitude found in U.S. data and is nearly four times larger for stocks trading with a registered dealer. However, this is largely explained by the time between trades and the bid‐ask spread. Unlike the U.S. data, the effect does not decline as stock price increases, probably because of a variable tick size in the Paris market. Finally, a change to a closing call auction in May 1996 for a subset of stocks did not reduce the day‐end effect.     

PRICE AND QUANTITY QUOTES ON NASDAQ: A STUDY OF DEALER QUOTATION BEHAVIOR

We show that the majority of quotes posted by NASDAQ dealers are noncompetitive and only 19.5% (18.4%) of bid (ask) quotes are at the inside. The percentage of dealer quotes that are at the inside is higher for stocks with wider spreads, fewer market makers, and more frequent trading, and lower for stocks with larger trade sizes and higher return volatility. These results support our conjecture that dealers have greater incentives to be at the inside for stocks with larger market‐making revenues and smaller costs. Dealers post large depths when their quotes are at the inside and frequently quote the minimum required depth when they are not at the inside. The latter quotation behavior leads to the negative intertemporal correlation between dealer spread and depth.     

Option trading after the opening bell and intraday stock return predictability

Prior literature finds that information is reflected in option markets before stock markets, but no study has explored whether option volume soon after market open has predictive power for intraday stock returns. Using novel intraday signed option-to-stock volume data, we find that a composite option trading score (OTS) in the first 30 min of market open predicts stock returns during the rest of the trading day. Such return predictability is greater for smaller stocks, stocks with higher idiosyncratic volatility, and stocks with higher bid–ask spreads relative to their options’ bid–ask spreads. Moreover, OTS is a significantly stronger predictor of intraday stock returns after overnight earnings announcements. The evidence suggests that option trading in the 30 min after the opening bell has predictive power for intraday stock returns.     

The Post-Reform Bid-Ask Spread Disparity between Nasdaq and the NYSE

We report further evidence of the difference in execution costs between Nasdaq and the NYSE before and after the 1997 market reforms. We find that informed trading costs are consistently higher on Nasdaq both before and after the reforms. In the pre‐reform period the Nasdaq‐NYSE disparity in bid‐ask spreads cannot be completely attributed to the difference in informed trading costs. However, in the post‐reform period the spread difference between these two markets becomes insignificant with the effect of informed trading costs controlled. Our findings are consistent with the contention that the reforms have largely reduced noninformation trading costs and dealers' rents.     

The determinants of quantile autocorrelations: Evidence from the UK

We empirically analyse the cross-sectional determinants of stock return autocorrelations in the UK in different quantiles of conditional return distributions. Autocorrelations in low quantiles are predominantly positive, whereas those in the remaining quantiles are negative. Autocorrelations in different quantiles depend on different sets of firm and trading characteristics: when returns are normal or high, prices react quickly to information, are driven by positive feedback traders, instantaneous news arrivals, and overshoot, trades are predominantly motivated by hedging/liquidity needs, and measured autocorrelations can be biassed by the bid–ask bounce effect and nonsynchronous trading. However, when returns are unusually low, prices are driven by information arriving sequentially and react sluggishly to it, and are influenced by trading on private information and/or negative feedback traders.     

Effect of the ban on short selling on market prices and volatility

We examine the effects of the short‐selling ban, imposed by Australian regulators in the wake of the global financial crisis, on the trading of financial stocks. Our findings argue against commonly stated reasons for imposing short‐sale bans. We find no evidence that short‐sale restrictions provide support for stock prices or that they reduce volatility. Moreover, stocks subject to the short‐selling ban suffered a severe degradation in market quality. Controlling for the adverse effects of the financial crisis on markets, we show that short‐selling restrictions increase intraday volatility, reduce trading activity and increase bid–ask spreads.     

Against the tide: the commencement of short selling and margin trading in mainland China

China's recent removal of short‐selling and margin trading bans on selected stocks enables testing of the relative effect of margin trading and short selling. We find the prices of the shortable stocks decrease, on average, relative to peer A‐shares and cross‐listed H‐shares, suggesting that short selling dominates margin trading effects. Contrary to the regulators' intention and recent developed market empirical evidence, liquidity declines and bid‐ask spreads increase in these shortable stocks. Consistent with Ausubel (1990), these results imply that uninformed investors avoid the shortable stocks to reduce the risk of trading with informed investors.     

Institutional Ownership and Return Reversals Following Short‐Term Return Consistency

Securities with consistently strong positive (negative) returns during the previous two weeks have future returns that are higher (lower) than those that do not. The results hold for various robustness checks, including those involving firm size, share turnover, past return levels, and bid‐ask bounce. The returns to short horizon consistency trading strategies are reliable through time and are both economically and statistically significant. There is also some evidence that longer periods of consistency lead to greater risk‐adjusted profits. Most surprising is that this effect holds only for those firms with high institutional ownership.     

The liquidity effects associated with addition of a stock to the S&P 500 index: evidence from bid/ask spreads

This study examines changes in stock liquidity, as measured by the bid/ask spread, when a stock is added to the S&P 500 Index. The paper presents evidence of a significant decrease in the bid/ask spread upon S&P 500 addition, however, this effect is limited to only those stocks that were not trading listed options. Further, the decrease in the bid/ask spread for nonoptioned stocks is accompanied by a significant and permanent increase in share price and trading volume. While optioned stocks experience a permanent increase in trading volume, they experience only a temporary increase in share price. The findings for optioned stocks support the hypothesis that the price and volume effects associated with S&P 500 addition derive from temporary price pressure. Findings pertaining to the nonoptioned stocks indicate that the price and volume effects associated with S&P addition reflect enhanced stock liquidity. The decrease in the bid/ask spread for nonoptioned stocks is attributed to informational efficiencies achieved via index arbitrage trading, and it is argued that this effect is mitigated for optioned stocks due to the pre-existence of arbitrage trading between the option and the underlying stock.     

Market Illiquidity and Conditional Equity Premium

We examine the time‐series relation between aggregate bid‐ask spreads and conditional equity premium. We document that average marketwide relative effective bid‐ask spreads forecast aggregate market returns only when controlling for average idiosyncratic variance. This control allows us to document the otherwise elusive relation between illiquidity and returns. The reason is that idiosyncratic variance correlates positively with spreads but has a negative effect on conditional equity premium, causing an omitted variable bias. Our results are robust to standard return predictors, alternative illiquidity measures, and out‐of‐sample tests. These findings are important because they provide strong support for the literature's conjecture that marketwide liquidity is an important asset pricing risk factor.     

Liquidity and valuation in an uncertain world

During the 2007–2009 financial crisis there was little or no trading in a variety of financial assets, even though bid and ask prices existed for many of these assets. We develop a model in which this illiquidity arises from uncertainty, and we argue that this new form of illiquidity makes bid and ask prices unsuitable as metrics for establishing “fair value” for these assets. We show how the extreme uncertainty that traders face can be characterized by incomplete preferences over portfolios, and we use Bewley's (2002) model of decision making under uncertainty to derive equilibrium quotes and the nonexistence of trading at these quotes. We then suggest alternatives for valuing assets in illiquid markets.