During my university time I worked on the IT help desk for a while. One day I received a call from a professor, who said that his printer had stopped working. So I asked him, if there was a message on the display and if he could read it to ...

In “What the hell is a variance matrix?” I talked about the basics of variance matrices and highlighted challenges for estimating them in finance.  Here we look more deeply at the most popular estimation technique. Models for variance matrices The types of variance estimates that are used in finance can ...

We think of accidents as abnormal events, but there is “normal accident” theory.  We don’t think of accidents happening in markets, but they do.  That’s why it’s called a market crash. For normal accidents to come into play, two conditions need to hold: the system is complex ...

The blog year started in August and consists of 30-something posts.  Here is a summary. Quant concepts backtesting: Backtesting — almost wordless cointegration: American TV does cointegration efficient frontier: Anomalies meet volatility implied alpha: Implied alpha — almost wordless portfolio theory: Ancient portfolio theory random walk: The tightrope of the random walk ...

As mentioned already here, while we were going to Québec City for the workshop, we had interesting discussions in the car, and Maciej mentioned an article recently published in The Actuary, Hence, I wanted to discuss (extremely) rare event probabi...

When I first came to finance, I kept hearing about “risk models”. I wondered, “What the hell is a risk model?” Of course, I didn’t say this out loud — that would have given the game away.  My wife has strict instructions that she is to be the only one ...