Asymptotic proportion of arbitrage points in fractional binary markets

A fractional binary market is an approximating sequence of binary models for the fractional Black-Scholes model, which Sottinen constructed by giving an analogue of the Donsker's theorem. In a binary market the arbitrage condition can be expressed as a condition on the nodes of a binary tree. We call "arbitrage points" the points in the binary tree which verify such an arbitrage condition and "arbitrage paths" the paths in the binary tree which cross at least one arbitrage point. Using this terminology, a binary market admits arbitrage if and only if there is at least one arbitrage point in the binary tree or equivalently if there is at least one arbitrage path. Following the lines of Sottinen, who showed that the arbitrage persists in the fractional binary market, we further prove that starting from any point in the tree, we can reach an arbitrage point. This implies that, in the limit, there is an infinite number of arbitrage points. Next, we provide an in-depth analysis of the asymptotic proportion of arbitrage points at asymptotic levels and of arbitrage paths in the fractional binary market. All these results are obtained by studying a rescaled disturbed random walk. We moreover show that, when $H$ is close to $1$, with probability $1$ a path in the binary tree crosses an infinite number of arbitrage points. In particular, for such $H$, the asymptotic proportion of arbitrage paths is equal to $1$

Market models with optimal arbitrage

We construct and study market models admitting optimal arbitrage. We say that a model admits optimal arbitrage if it is possible, in a zero-interest rate setting, starting with an initial wealth of 1 and using only positive portfolios, to superreplicate a constant c>1. The optimal arbitrage strategy is the strategy for which this constant has the highest possible value. Our definition of optimal arbitrage is similar to the one in Fernholz and Karatzas (2010), where optimal relative arbitrage with respect to the market portfolio is studied. In this work we present a systematic method to construct market models where the optimal arbitrage strategy exists and is known explicitly. We then develop several new examples of market models with arbitrage, which are based on economic agents' views concerning the impossibility of certain events rather than ad hoc constructions. We also explore the concept of fragility of arbitrage introduced in Guasoni and Rasonyi (2012), and provide new examples of arbitrage models which are not fragile in this sense

Are There Arbitrage Opportunities in Credit Derivatives Markets? A New Test and an Application to the Case of CDS and ASPs

This paper analyzes possible arbitrage opportunities in credit derivatives markets using selffinancing strategies combining Credit Default Swaps and Asset Swaps Packages. We present a new statistical arbitrage test based on the subsampling methodology which has lower Type I error than existing alternatives. Using four different databases covering the period from 2005 to 2009, long-run (cointegration) and statistical arbitrage analysis are performed. Before the subprime crisis, we find long-run arbitrage opportunities in 26% of the cases and statistical arbitrage opportunities in 24% of the cases. During the crisis, arbitrage opportunities decrease to 8% and 19%, respectively. Arbitrage opportunities are more frequent in the case of relatively low rated bonds and bonds with a high coupon rate

Universal Arbitrage Aggregator in Discrete Time Markets under Uncertainty

In a model independent discrete time financial market, we discuss the richness of the family of martingale measures in relation to different notions of Arbitrage, generated by a class $\mathcal{S}$ of significant sets, which we call Arbitrage de la classe $\mathcal{S}$. The choice of $\mathcal{S}$ reflects into the intrinsic properties of the class of polar sets of martingale measures. In particular: for S=${\Omega}$ absence of Model Independent Arbitrage is equivalent to the existence of a martingale measure; for $\mathcal{S}$ being the open sets, absence of Open Arbitrage is equivalent to the existence of full support martingale measures. These results are obtained by adopting a technical filtration enlargement and by constructing a universal aggregator of all arbitrage opportunities. We further introduce the notion of market feasibility and provide its characterization via arbitrage conditions. We conclude providing a dual representation of Open Arbitrage in terms of weakly open sets of probability measures, which highlights the robust nature of this concept

The Mirage of Triangular Arbitrage in the Spot Foreign Exchange Market

We investigate triangular arbitrage within the spot foreign exchange market using high-frequency executable prices. We show that triangular arbitrage opportunities do exist, but that most have short durations and small magnitudes. We find intra-day variations in the number and length of arbitrage opportunities, with larger numbers of opportunities with shorter mean durations occurring during more liquid hours. We demonstrate further that the number of arbitrage opportunities has decreased in recent years, implying a corresponding increase in pricing efficiency. Using trading simulations, we show that a trader would need to beat other market participants to an unfeasibly large proportion of arbitrage prices to profit from triangular arbitrage over a prolonged period of time. Our results suggest that the foreign exchange market is internally self-consistent and provide a limited verification of market efficiency

Are There Arbitrage Opportunities in Credit Derivatives Markets? A New Test and an Application to the Case of CDS and ASPs

This paper analyzes possible arbitrage opportunities in credit derivatives markets using selffinancing strategies combining Credit Default Swaps and Asset Swaps Packages. We present a new statistical arbitrage test based on the subsampling methodology which has lower Type I error than existing alternatives. Using four different databases covering the period from 2005 to 2009, long-run (cointegration) and statistical arbitrage analysis are performed. Before the subprime crisis, we find long-run arbitrage opportunities in 26% of the cases and statistical arbitrage opportunities in 24% of the cases. During the crisis, arbitrage opportunities decrease to 8% and 19%, respectively. Arbitrage opportunities are more frequent in the case of relatively low rated bonds and bonds with a high coupon rate.statistical arbitrage, credit derivatives, credit spreads, cointegration, subsampling

Weak and strong no-arbitrage conditions for continuous financial markets

We propose a unified analysis of a whole spectrum of no-arbitrage conditions for finan- cial market models based on continuous semimartingales. In particular, we focus on no-arbitrage conditions weaker than the classical notions of No Arbitrage opportunity (NA) and No Free Lunch with Vanishing Risk (NFLVR). We provide a complete characterization of the considered no-arbitrage conditions, linking their validity to the characteristics of the discounted asset price process and to the existence and the properties of (weak) martingale deflators, and review classical as well as recent results