In the Aymara language the past is in front and the future is behind. It is rare for languages (at least existing ones) to have the metaphor turned this way. But it makes sense to me — maybe it’s the quant in me. We can see the past, and the most recent past is the … Continue reading
Portfolio Probing
Factor models of variance in finance
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 be classified as: Sample estimate … Continue reading
Posted in R language, Risk
Tagged covariance matrix, factor model, risk model, variance matrix
10 Comments
Upcoming Events
2011 March 08, 8:00 AM, London EDHEC Risk Institute presents: Raman Uppal How to (or how not to) manage money New approaches for portfolio construction. Admission is free, but registration (soon) is required. More details in the brochure (pdf) 2011 March 08 6PM, London The LondonR meeting. Details at http://www.londonr.org/ 2011 March 09 6:30, New … Continue reading
An investment lottery
Can fund managers capture money that is now gambled away? Investing versus gambling A clean, though imperfect, distinction between investing and gambling is: if the expected return is positive, it is investing if the expected return is negative, it is gambling Other views on gambling versus investing can be found here and here. An investing … Continue reading
Inflexible regime, inflexible prices
There is a deep connection between political mechanisms and economic mechanisms, at least according to Ajay Shah. Price flexibility Ajay Shah has a post called Jittery regimes fix prices. It is well worth reading the whole piece (which isn’t very long anyway). Here’s an excerpt: Flexible prices are constantly disruptive. Every day, there are a … Continue reading
Posted in Economics, Fund management in general, Quant finance
1 Comment
Thalesians: events and videos
The Thalesians is a group that has been going for a few years in London, and is just about to have its first event in New York. It holds events on various topics that are generally not far from quantitative finance. Events The first New York talk will be held Wednesday 2011 February 23. Gerald … Continue reading
Who are the innocent bystanders?
High volatility stocks are, in general, nonsensical. Who’s to blame? The high vol gamble Theory says that investors demand higher returns for higher volatility assets. Reality says that the most volatile stocks have the lowest expected returns. See, for example, The volatility puzzle solved? — specifically Figure 2. That this particular theory doesn’t hold means … Continue reading
A tangle of luck and skill
Some concrete steps for discerning skill from luck. The Harvard Business Review published a guest blog post by Michael Mauboussin called Untangling Skill and Luck. That post is really a brief introduction to a longer piece which is also called Untangling Skill and Luck. The punchline is that there are ways of estimating the proportion … Continue reading
Quantitative finance now on Stack Exchange
The site is http://quant.stackexchange.com/ A new area has emerged in Stack Exchange for Quantitative Finance (in trying to spell that I now know why it is usually just “quant”). It has been in private beta for a few weeks and has become public in the last few days. Already it has reasonable traffic. I predict … Continue reading
Posted in Quant finance
1 Comment
4 and a half myths about beta in finance
Much of what has been said and thought about beta in finance is untrue. Myth 1: beta is about volatility This myth is pervasive. Beta is associated with the stock’s volatility but there is more involved. Beta is the ratio of the volatility of the stock to the volatility of the market times the correlation … Continue reading
Posted in Quant finance, R language
Tagged beta in finance, Capital Asset Pricing Model, CAPM, statistical bootstrap
12 Comments
