Arbitraging Arbitrageurs

This paper develops a theory of strategic trading in markets with large arbitrageurs. If arbitrageurs are not well capitalized, capital constraints make their trades predictable. Other market participants can exploit this by trading against them. Competitors may find it optimal to lend to arbitrageurs that are financially fragile; additional capital makes the arbitrageurs more viable, and lenders can reap profits from trading against them for a longer time. The strategic behavior of these market participants has implications for the functioning of financial markets. Strategic trading may produce significant price distortions, increase price manipulation, and trigger forced liquidations of large traders.     

Interpreting Factor Models

We argue that tests of reduced‐form factor models and horse races between “characteristics” and “covariances” cannot discriminate between alternative models of investor beliefs. Since asset returns have substantial commonality, absence of near‐arbitrage opportunities implies that the stochastic discount factor can be represented as a function of a few dominant sources of return variation. As long as some arbitrageurs are present, this conclusion applies even in an economy in which all cross‐sectional variation in expected returns is caused by sentiment. Sentiment‐investor demand results in substantial mispricing only if arbitrageurs are exposed to factor risk when taking the other side of these trades.     

Index arbitrage and the pricing relationship between Australian stock index futures and their underlying shares

This paper examines the mispricing of Australian stock index futures. Exogenous and endogenous price volatility is confirmed to have a positive impact on the mispricing spread, after filtering out predictable time series components. More accurate pricing associated with surprise trading volume in the underlying stocks is consistent with arbitrageurs acting to narrow price disparities relative to the futures market. Ex‐ante interest rate volatility is the primary source of risk faced by arbitrageurs and fluctuations in the transaction cost of opening index arbitrage positions influence the extent to which they drive prices towards theoretical fair values.     

Inference,arbitrage, and asset price volatility

Does the presence of arbitrageurs decrease equilibrium asset price volatility? I study an economy with arbitrageurs, informed investors, and noise traders. Arbitrageurs face a trade-off between “inference” and “arbitrage”: they would like to buy assets in response to temporary price declines—the arbitrage effect—but sell when prices decline permanently—the inference effect. In equilibrium, the presence of arbitrageurs increases volatility when the inference effect dominates the arbitrage effect. From a technical point of view, the paper offers closed form solutions to a dynamic equilibrium model with asymmetric information and non-Gaussian priors.     

Overcoming limits of arbitrage: Theory and evidence

Limits to arbitrage arise because financial intermediaries may face funding constraints when mispricing worsens. Using a model with limits to arbitrage, where we allow arbitrageurs to secure capital even in case of underperformance, we show that arbitrageurs that are more protected from withdrawals have more mean-reverting and volatile returns. Using data on hedge fund performance, we find robust support for these hypotheses: Funds with contractual impediments to withdrawals, and funds with performance-insensitive outflows, recover more quickly after a bad year and have more volatile returns. Our evidence is consistent with the idea that some hedge funds overcome the limits to arbitrage.     

Noise as Information for Illiquidity

We propose a market‐wide liquidity measure by exploiting the connection between the amount of arbitrage capital in the market and observed “noise” in U.S. Treasury bonds—the shortage of arbitrage capital allows yields to deviate more freely from the curve, resulting in more noise in prices. Our noise measure captures episodes of liquidity crises of different origins across the financial market, providing information beyond existing liquidity proxies. Moreover, as a priced risk factor, it helps to explain cross‐sectional returns on hedge funds and currency carry trades, both known to be sensitive to the general liquidity conditions of the market.     

Trading and arbitrage in cryptocurrency markets

Cryptocurrency markets exhibit periods of large, recurrent arbitrage opportunities across exchanges. These price deviations are much larger across than within countries, and smaller between cryptocurrencies, highlighting the importance of capital controls for the movement of arbitrage capital. Price deviations across countries co-move and open up in times of large bitcoin appreciation. Countries with higher bitcoin premia over the US bitcoin price see widening arbitrage deviations when bitcoin appreciates. Finally, we decompose signed volume on each exchange into a common and an idiosyncratic component. The common component explains 80% of bitcoin returns. The idiosyncratic components help explain arbitrage spreads between exchanges.     

Idiosyncratic Volatility and Firm‐Specific News: Beyond Limited Arbitrage

We examine the relation between idiosyncratic volatility and returns around news announcements. Mispricing is most likely to occur during news announcements. If idiosyncratic volatility generates a limit to arbitrage, then the negative relation between returns and news volatility should be stronger than the relation to nonnews volatility. Instead, we find nonnews volatility has a robust negative relation to returns and lacks key features expected if volatility were a reflection of limits to arbitrage. Pricing of nonnews volatility is related to lottery‐like features of a stock's return. Our results suggest that volatility has a price effect beyond a limit to arbitrage.     

Reduction of Constraints on Arbitrage Trading and Market Efficiency: An Examination of Ex-Day Returns in Hong Kong after Introduction of Electronic Settlement

Previous research documents positive ex-dividend day returns in excess of one percent in the unique institutional setting of Hong Kong, where neither dividends nor capital gains are taxed. Short-term arbitrage trades around the ex-day were hampered by physical settlement procedures. After the recent switch to an electronic settlement system, which enables such trades, ex-day abnormal returns have declined to an insignificant 0.17 percent. This drop is more pronounced for high-yield stocks, which are more likely to attract dividend capture trading. The evidence points to the crucial role of short-term traders in ensuring the pricing efficiency of financial markets.     

Nonfinancial Firms as Cross‐Market Arbitrageurs

I demonstrate that nonfinancial corporations act as cross‐market arbitrageurs in their own securities. Firms use one type of security to replace another in response to shifts in relative valuations, inducing negatively correlated financing flows in different markets. Net equity repurchases and net debt issuance both increase when expected excess returns on debt are particularly low, or when expected excess returns on equity are relatively high. Credit valuations affect equity financing as much as equity valuations do, and vice versa. Cross‐market corporate arbitrage is most prevalent among large, unconstrained firms, and helps account for aggregate financing patterns.     

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.     

Arbitrage and the Law of One Price in the market for American depository receipts

Ours is the first paper to highlight pairs trading as the main price-correcting mechanism by which arbitrage can maintain stock–ADR parity. We show that arbitraging stock–ADR pairs extracts small per-trade profits which accumulate to a substantial aggregate return. The observed strong tendency of pricing disequilibria to mean-revert, along with the two-way convertibility between stocks and ADRs, mean that arbitrageurs face minimal risks toward price divergence. They do, however, face uncertainty about the duration of individual trades. The magnitude of this uncertainty relates directly to the profit target arbitrageurs set after a long/short position is established. This fact can explain why some disequilibria go unexploited. Overall, our work provides evidence against automatically efficient prices, and supports the view that mispricings incentivize arbitrageurs to enforce market efficiency.     

A Test of the Modigliani‐Miller Invariance Theorem and Arbitrage in Experimental Asset Markets

Modigliani and Miller show that the total market value of a firm is unaffected by a repackaging of asset return streams to equity and debt if pricing is arbitrage‐free. We investigate this invariance theorem in experimental asset markets, finding value‐invariance for assets of identical risks when returns are perfectly correlated. However, exploiting price discrepancies has risk when returns have the same expected value but are uncorrelated, in which case the law of one price is violated. Discrepancies shrink in consecutive markets, but persist even with experienced traders. In markets where overall trader acuity is high, assets trade closer to parity.     

Determinants and implications of arbitrage holdings in acquisitions

We find evidence of passive and active roles for arbitrageurs in the acquisition process. Using a simultaneous-equation framework to recognize endogeneity, we analyze 608 acquisition bids over the 1992–1999 period. Our results indicate that the change in arbitrage holdings is greater in successful offers. However, changes in arbitrage holdings are also related to the probability of success, bid premia, and arbitrage returns. In addition, the change in arbitrage holdings is positively associated with both revision returns and the occurrence of subsequent bids. Overall, we find that merger arbitrageurs play an important role in the market for corporate control.     

Does the law of one price hold in international financial markets? Evidence from tick data

This paper investigates the validity of the law of one price (LOP) in international financial markets by examining the frequency, size and duration of inter-market price differentials for borrowing and lending services (‘one-way arbitrage’). Using a unique data set for three major capital and foreign exchange markets that covers a period of more than seven months at tick frequency, we find that the LOP holds on average, but numerous economically significant violations of the LOP arise. The duration of these violations is high enough to make it worthwhile searching for one-way arbitrage opportunities in order to minimize borrowing costs and/or maximize earnings on given funds. We also document that such opportunities decline with the pace of the market and increase with market volatility.     

The Intraday Relation between NYSE and CBOE Prices

I extend the literature regarding price discovery across stock and option markets through an empirical model that allows information to flow through an error‐correction term and volatility. NYSE prices tend to lead CBOE prices by at least thirty minutes over the entire six‐year sample period. In addition, informed trading in the options market is revealed more strongly through persistence in volatility and the spillover of volatility to the stock market than it is through returns.     

Cross‐Asset Speculation in Stock Markets

In practice, heterogeneously informed speculators combine private information about multiple stocks with information in prices, taking into account how their trades influence the inferences of other speculators via prices. We show how this speculation causes prices to be more correlated than asset fundamentals, raising price volatility. The covariance structure of asset fundamentals drives that of prices, while the covariance structure of liquidity trade drives that of order flows. We characterize how speculator profits vary with the distributions of information and liquidity trade across assets and speculators, and relate the cross‐asset factor structure of order flows to that of returns.     

INFORMATION AND NOISE IN FINANCIAL MARKETS: EVIDENCE FROM THE E‐MINI INDEX FUTURES

I examine the informational contributions and effects on transitory volatility of trades initiated by different types of traders in three actively traded index futures markets. The results show that trades initiated by exchange member firms account for more than 60% of price discovery during the trading day. These institutional trades appear to be more informative than trades of individual exchange members or off‐exchange traders. I also find that off‐exchange traders introduce more noise into the prices than do exchange members. My findings provide new evidence on the role of different types of traders in the price formation process.     

Optimal portfolio selection in nonlinear arbitrage spreads

This paper analytically solves the portfolio optimization problem of an investor faced with a risky arbitrage opportunity (e.g. relative mispricing in equity pairs). Unlike the extant literature, which typically models mispricings through the Ornstein–Uhlenbeck (OU) process, we introduce a nonlinear generalization of OU which jointly captures several important risk factors inherent in arbitrage trading. While these factors are absent from the standard OU, we show that considering them yields several new insights into the behavior of rational arbitrageurs: Firstly, arbitrageurs recognizing these risk factors exhibit a diminishing propensity to exploit large mispricings. Secondly, optimal investment behavior in light of these risk factors precipitates the gradual unwinding of losing trades far sooner than is entailed in existing approaches including OU. Finally, an empirical application to daily FTSE100 pairs data shows that incorporating these risks renders our model's risk-management capabilities superior to both OU and a simple threshold strategy popular in the literature. These observations are useful in understanding the role of arbitrageurs in enforcing price efficiency.     

On the role of arbitrageurs in rational markets

We investigate the role of “arbitrageurs,” who exploit price discrepancies between redundant securities. Arbitrage opportunities arise endogenously in an economy populated by rational, heterogeneous investors facing investment restrictions. We show that an arbitrageur alleviates these restrictions and improves the transfer of risk amongst investors. When the arbitrageur behaves noncompetitively, taking into account the price impact of his trades, he optimally limits the size of his positions due to his decreasing marginal profits. When the arbitrageur is subject to margin requirements and is endowed with capital from outside investors, the size of his trades and capital are endogenously determined in equilibrium.