This article argues that the temporality of the financial economy ought to be seen as radically synchronistic. ‘Synchronism’ refers to both an epistemological and practical approach that addresses finance neither with a view to the past nor to the future, but is instead focused on the moment that a financial transaction is settled (i.e., the horizon of trading). From this perspective, the article expands the scope of current social theorizing on financial markets, which is characterized by a preoccupation with the futurity of financial markets and products. It suggests that financial synchronism can be traced back to certain developments in economic theory since the so-called ‘marginalist revolution’, which enabled the transfer of a certain optics informing market theories into financial practices. On these terms, financial synchronism is interpreted as a powerful social imaginary that crucially mediates the way contemporary societies face the contingency of the future.

This paper considers the pricing of long-term options on assets such as housing, where either government intervention or the economic nature of the asset limits large falls in prices. The observed asset price is modelled by a geometric Brownian motion (“the notional price”) reflected at a lower barrier. The resulting observed price has standard dynamics but with localised intervention at the barrier, which allows arbitrage with interim losses; this is funded by the government’s unlimited powers of intervention, and its exploitation is subject to credit constraints. Despite the lack of an equivalent martingale measure for the observed price, options on this price can be expressed as compound options on the arbitrage-free notional price, to which standard risk-neutral arguments can be applied. Because option deltas tend to zero when the observed price approaches the barrier, hedging with the observed price gives the same results as hedging with the notional price and so exactly replicates option payoffs. Hedging schemes are not unique, with the cheapest scheme for any derivative being the one which best exploits the interventions at the barrier. The price of a put is clear: direct replication has a lower initial cost than synthetic replication, and the replication portfolio always has positive value. The price of a call is ambiguous: synthetic replication has a lower initial cost than direct replication, but the replication portfolio may give interim losses. So the preferred replication strategy (and hence price) of a call depends on what margin payments need to be made on these losses.

Following a review of the etymology and modern usage of the term ‘arbitrage’, this article explores the relevance of historical context to possible instances of ancient arbitrage activity. Types of possible ‘arbitrage’ associated with the use of overvalued coinage in regions of Greek influence are considered. Comparison with Roman civilization reveals the relevance of social attitudes and legal institutions to the ability to execute arbitrage trades. Specific attention is given to the possibility of arbitrage across the Roman frontier to India and the impact of debasements during the imperial period. Recognizing that sources prior to early modern times are scant, numismatic, epigraphic and literary evidence that is available to make inferences about ancient arbitrage activity is assessed.

We introduce and study the notion of sure profits via flash strategies, consisting of a high-frequency limit of buy-and-hold trading strategies. In a fully general setting, without imposing any semimartingale restriction, we prove that there are no sure profits via flash strategies if and only if asset prices do not exhibit predictable jumps. This result relies on the general theory of processes and provides the most general formulation of the well-known fact that, in an arbitrage-free financial market, asset prices (including dividends) should not exhibit jumps of a predictable direction or magnitude at predictable times. We furthermore show that any price process is always right-continuous in the absence of sure profits. Our results are robust under small transaction costs and imply that, under minimal assumptions, price changes occurring at scheduled dates should only be due to unanticipated information releases.

Under proportional transaction costs, a price process is said to have a consistent price system, if there is a semimartingale with an equivalent martingale measure that evolves within the bid-ask spread. We show that a continuous, multi-asset price process has a consistent price system, under arbitrarily small proportional transaction costs, if it satisfies a natural multi-dimensional generalization of the stickiness condition introduced by Guasoni (2006).

Received internationalization theory argues that firms occupy domestic space before going abroad; in other words, large, oligopolistic firms are most likely to internationalize. The experience of China, whose economy is fragmented and whose firms are small by global standards, suggests otherwise. We construct a model of small firm internationalization driven by the relative transaction costs of crossing domestic (in the case of China, provincial) and international borders. When the costs of crossing domestic borders exceed the costs of crossing international borders, firms will internationalize at a relatively early stage of development. In the case of China, local protectionism and inefficient domestic logistics increase the costs of doing business domestically; moreover, protection of property rights in the West and the advantages afforded Chinese owned firms reconstituted as foreign entities operating in China decrease the costs of ‘going out’. We coin the term ‘institutional arbitrage’ to capture Chinese firms' pursuit of efficient institutions outside of China. We argue that strategic exit from the home country rather than strategic entry into foreign markets may explain the internationalization of many Chinese firms.

There has recently been some debate about the usefulness of financial economics to the actuarial profession. The consensus appears to be that the techniques are potentially valuable, but the published material is not quite ‘oven ready’. Some development work is required before the material can be applied.

The author has carried out much of the necessary development work on behalf of various clients over the last few years. On some occasions the results have conflicted with more conventional actuarial methods. The main aim of the paper is to bring the new techniques into the public domain so that they can be properly discussed by the profession, and adopted more widely if appropriate.

The paper contains a number of worked examples using techniques developed by financial economists. The author has listed the computer code which generated the examples and deposited copies on the Internet, so that others can explore the issues with a minimal development overhead.

In recent years there has been a trend towards market consistent valuation in those institutions for which actuaries have responsibilities. The larger United Kingdom with-profits insurance companies are now preparing realistic balance sheets, both for internal purposes and also at the request of the Financial Services Authority. International accounting standards have been moving to a fair value approach. Pension fund accounting under FRS 17 has also moved in this direction.

In this paper we examine the reasons for the adoption of market consistent valuation and discuss some of the commercial implications and corporate valuation. We consider the methods and assumptions which can be used to develop market consistent valuations of cash flows typically encountered in the liabilities of financial institutions, together with some of the problems inherent in the calibration of models used for the valuation of these cash flows. The volatility assumption is crucial to the valuation of options and guarantees, and we discuss the relationship between historical and implied volatility.

While most insurance companies initially adopted formulae to value their with-profits guarantees, several offices are now using a Monte Carlo simulation approach for their realistic balance sheets. The Monte Carlo approach enables allowance to be made for management discretion in bonus and investment policy, as well as policyholder actions. However, in many cases it is possible to develop analytical formulae for cash flows approximating those payable under insurance contracts.

The valuation formulae have implications for the hedging of embedded guarantees. The authors discuss the construction of hedges for financial risks in with-profits funds, the separate perspectives of policyholders and shareholders, possible funds in which to hold hedging instruments, limitations of capital market hedging tools and the effect of taxation on hedge effectiveness.

The paper opens by showing how certain types of hedge funds can reduce the risk and increase the return on a traditional balanced managed fund. One of the key characteristics of such a hedge fund is that it has a low correlation with the balanced managed fund. The paper puts forward a new way of explaining correlation so that it can be more readily understood, and suggests methods of analysis for dealing with the fact that correlation is unstable. Volatility correlation is also examined because of its importance in reducing the risk of a portfolio.

An outline of the characteristics and risks of three types of hedge funds, namely, long/short equity, convertible arbitrage and merger arbitrage, together with some questions investors might put to prospective hedge fund managers is given in Section 5.

Some of the very basic statistical analysis techniques used in assessing the past performance of hedge funds are given in Section 6. Considerable emphasis is put on the need to examine daily return data as an insight into the quality of the manager's IT systems, his risk management, evidence of smoothing of returns, and to gain access to a higher number of data points for assessing the repeatability of performance.

An entire section of the paper is devoted to gaining a clear understanding of a prospective hedge fund manager's volatility management strategy because of its importance in the context of the fee structure of hedge funds and its importance for assessing the ability of a hedge fund to reduce the risk and increase the returns of a balanced managed fund.

Funds of hedge funds are examined in the final section, and the section concludes that large sophisticated institutional investors may wish to create a portfolio of hedge funds rather than invest in a fund of hedge funds.

Several countries have made community rating mandatory for certain lines of insurance, particularly health insurance. This paper offers a theoretical solution to the problem of designing equalisation schemes to support community rating in a market where different insurers are selling different benefit plans. The criterion chosen is that an equalisation scheme should minimise the opportunities for arbitrage between insurers, which community rating otherwise would generate. Several possible measures of arbitrage are presented, and the optimal schemes are compared against data from Australian health insurers. Finally, the approach is extended to partial community rating, for example unisex rating.

Constraints imposed on premium calculation principles are studied under one aspect of competitive market theory: the impossibility of systematic arbitrage. Principles based on second moments or utility theory are shown to lead to arbitrage possibilities, while some other principles do not.

The theory of finite security markets developed by Harrison and Pliska [1] used the separating hyperplane theorem to establish the relationship between the lack of arbitrage opportunities and the existence of a certain martingale measure. In this paper we treat this theory by examining certain geometric properties of the sample paths of the price process, that is, we focus on the price increments of the stocks between one time period to the next and convert them to martingale differences through an equivalent change of measure. Thus, in contrast to Harrison and Pliska&s functional analytic derivation, our approach is based on probabilistic methods and allows a geometric interpretation which not only provides a connection to linear programming but also yields an algorithm for analyzing finite security markets. Moreover, we can make precise the connection between diverse expressions of economic equilibrium such as ‘absence of arbitrage’, ‘martingale property, and ‘complementary slackness property’.