1
Introduction

In 2007, a global financial crisis (GFC) started which eventually became more severe and long-lasting than could have ever been anticipated. Along the way, there were major casualties such as the bankruptcy of the investment bank Lehman Brothers. Governments around the world had to bailout other financial institutions such as American International Group (AIG) in the US and the Royal Bank of Scotland in the UK.

The GFC caused a major focus on counterparty credit risk (CCR) which is the credit risk in relation to derivative products. A derivative trade is a contractual relationship that may be in force from a few days to several decades. During the lifetime of the contract, the two counterparties have claims against each other such as in the form of cash flows that evolve as a function of underlying assets and market conditions. Derivatives transactions create CCR due to the risk of insolvency of one party. This CCR in turn creates systemic risk due to derivatives trading volume being dominated by a relatively small number of large derivatives counterparties (‘dealers’) that are then key nodes of the financial system.

Post-GFC, participants in the derivatives market became more aware of CCR and its quantification via credit value adjustment (CVA). They also started to create more value adjustments, or xVAs, in order to quantify other costs such as funding, collateral, and capital. Derivatives pricing used to be focused on so-called ‘exotics’ with the majority of simple or vanilla derivatives thought to be relatively straightforward to deal with. However, the birth of xVA has changed this and even the most simple derivatives may have complex pricing and valuation issues arising from xVA.

Regulation has also enhanced the need to consider xVA (or XVA). Increasing capital requirements, constraints on funding, liquidity, and leverage together with a clearing mandate and bilateral margin requirements all make derivatives trading more expensive and complex. However, derivatives are still fundamentally important: for example, without them end users would have to use less effective hedges, which would create income statement volatility. The International Swaps and Derivatives Association (ISDA 2014b) reports that 85% of end users said that derivatives were very important or important to their risk management strategy and 79% said they planned to increase or maintain their use of over-the-counter (OTC) derivatives.

This book aims to fully explain xVA and the associated landscape of derivatives trading. Chapters 2 to 5 will discuss the basics of derivatives, regulation, CCR, and introduce the concept of xVA. Chapters 6 to 10 will discuss risk mitigation methods such as netting, margining, and central clearing. Chapters 11 to 15 will cover the building blocks of xVA such as exposure, credit spreads, funding, and capital costs. Finally, Chapters 16 to 20 will define the xVAs in sequence whilst also discussing their relationships to one another. Chapter 21 will discuss the ‘xVA desk’ and management of xVA.

The online Appendices and Spreadsheets provide more detail on various xVA calculations. This book is a relatively non-mathematical treatment of xVA. For a more mathematically-rigorous text for quantitative researchers, Andrew Green's book (Green 2015) is strongly recommended.