Category Archives: Blog
Miles of iles
An explanation of quartiles, quintiles deciles, and boxplots. Previously “Again with variability of long-short decile tests” and its predecessor discusses using deciles but doesn’t say what they are. The *iles These are concepts that have to do with approximately equally sized groups created from sorted data. There are 4 groups with quartiles, 5 with quintiles … Continue reading
Posted in Quant finance, R language
Tagged boxplot, decile, interquartile range, IQR, quartile, quintile
12 Comments
A look at historical Value at Risk
Historical Value at Risk (VaR) is very popular because it is easy and intuitive: use the empirical distribution of some specific number of past returns for the portfolio. Previously “The estimation of Value at Risk and Expected Shortfall” included an R function to estimate historical VaR. Generating portfolios A useful tool to explore risk models … Continue reading
garch and the Algorithmic Trading Conference
The Imperial College Algorithmic Trading Conference was Saturday. Talks Massoud Mussavian Massoud gave a great talk on “Algo Evolution”. It started with a historical review of how trading used to be done “by hand”. It culminated in a phylogenetic tree of trading algorithms. There was an herbivore branch and a carnivore branch. Robert Macrae Robert … Continue reading
Posted in Quant finance, R language
Tagged Algorithmic Trading Conference, garch, volatility clustering
6 Comments
Again with variability of long-short decile tests
A simpler approach to producing the variability. Previously The post “Variability in long-short decile strategy tests” proposed a way of assessing the variability of strategy tests in which a long-short portfolio is created by equally weighting the top and bottom deciles. Improved idea Joe Mezrich suggests maintaining equal weights but bootstrapping the assets within the … Continue reading
Variability in long-short decile strategy tests
How to capture return variability when testing strategies with long-short deciles. Traditional practice Question: Does variable X have predictive power for our universe of assets? A common scheme of quants to answer the question is to form a series of portfolios over time. The portfolio at each time point: is long the equal weighting of … Continue reading
Discovering the quality of portfolio decisions
Performance analysis of an example portfolio. The portfolio We explore a particular portfolio during 2007. It invests in S&P 500 stocks and starts the year with a value of $10 million. Initially there are 50 names in the portfolio. It also ends the year with 50 names but has up to 53 names during the … Continue reading
Upcoming events
New Events Thalesians (London) 2012 November 21: Isabel Ehrlich on “Basket Options with Smile”. Abstract: Due to the distinct lack of models for basket options that remain consistent with the market smile we look at approximations that are able to accurately replicate the volatility smile. Notably we turn to the use of an Edgeworth series … Continue reading
Posted in Events, R language
Leave a comment
The estimation of Value at Risk and Expected Shortfall
An introduction to estimating Value at Risk and Expected Shortfall, and some hints for doing it with R. Previously “The basics of Value at Risk and Expected Shortfall” provides an introduction to the subject. Starting ingredients Value at Risk (VaR) and Expected Shortfall (ES) are always about a portfolio. There are two basic ingredients that … Continue reading
Posted in R language, Risk
Tagged Conditional Value at Risk, Expected Shortfall, Value at Risk
2 Comments
