Iceberg Risk2002
An Adventure in Portfolio Theory
by Kent Osband
"For all the supposed sophistication and accuracy of quantitative risk models, one key question continues to haunt portfolio managers. Why are stock market crashes and other market outliers so much more frequent than standard portfolio theory predicts?".
"The answer is dismayingly simple. Standard theory is so wedded to normal "bell-shaped" risks that it assumes the outliers away. This simplifies calculations and makes for innocuous auditors' reports. But the approach is fundamentally flawed. With a few exceptions, it cannot capture the risks that large chunks of your portfolio soar or dive together.".
"Iceberg Risk exposes this crucial limitation through an engaging mixture of story, charts, and math. Statistical concepts are developed intuitively first, and all algebra is cordoned off...