The Number That Killed Us: A Story of Modern Banking, Flawed Mathematics, and a Big Financial Crisis

A critical look at the risk measurement tool that has repeatedly hurt the financial world

The Number That Killed Us finally tells the "greatest story never told": how a mysterious financial risk measurement model has ruled the world for the past two decades and how it has repeatedly, and severely, caused market, economic, and social turmoil. This model was the key factor behind the unleashing of the cataclysmic credit crisis that erupted in 2007 and which the effects are still being felt around the world. The Number That Killed Us is the first and only book to thoroughly explain this hitherto-uncovered phenomenon, making it the key reference for truly understanding why the malaise took place.

The very number financial institutions and regulators use to measure risk (Vale at Risk/VaR) has masked it, allowing firms to leverage up their speculative bets to unimaginable levels. VaR sanctioned and allowed the monstrously geared toxic punts that sank Wall Street, and the world, during the latest crisis. We can confidently say that VaR was the culprit. In The Number That Killed Us, derivatives expert Pablo Triana takes you through the development of VaR and shows how its inevitable structural flaws allowed banks to take on even greater risks. The precise role of VaR in igniting the latest crisis is thoroughly covered, including in-depth analysis of how and why regulators, by falling in love with the tool, condemned us to chaos. Uncritically embraced worldwide for way too long, VaR is, in the face of such destruction, just starting to be examined as problematic, and in this book Triana (long an open critic of the tool's role in encouraging mayhem) uncovers exactly why it makes our financial world a more dangerous place. If we care for our safety, we should let VaR go.

• Contains controversial analysis of the hotly debated risk metric Value at Risk (VaR) and its central role in the credit crisis
• Denounces the role of regulators and academics in forcing the presence of the inevitably malfunctioning in financeland
• Describes how bonus-hungry traders can use VaR as an alibi to take on the most reckless of bets
• Reveals how the most recent financial crisis will simply repeat itself if the problems behind VaR are not unmasked
• Pablo Triana is also the author of Lecturing Birds on Flying

The very risk measurement tool that was intended to contain risk allowed financial firms to blindly take on more. The model that was supposed to save us condemned us to misery. The Number That Killed Us reveals how this has happened and what needs to be done to correct the situation.

Pablo Triana is a professor at ESADE Business School, and the author of Lecturing Birds On Flying (also by Wiley) and Corporate Derivatives. He has published widely on risk management, derivatives, and banking regulation in many of the world’s leading financial and business imprints. He has held various roles in the financial industry.