Articles by Dzidorius Martinaitis

Plotting git statistics

July 13, 2011 | Dzidorius Martinaitis

Here’s a funny story – friend of my, avid gamer at that time, was going downhill on a bicycle when wonderful idea flashed his mind: I need to save the current status… Just in case if I crash, I will start again from the top of the hill. If you ... [Read more...]

Artificial intelligence in trading: k-means clustering

July 6, 2011 | Dzidorius Martinaitis

There is many flavors of artificial intelligence (AI), however I want to show practical example of the cluster analysis. It is very applicable in finance. For example, one of stylized facts of volatility is, that it moves in clusters, meaning that today’s volatility will be more likely as yesterday’... [Read more...]

timezone issue in R

May 14, 2011 | Dzidorius Martinaitis

While investigating Intraday patterns in FX returns and order flow paper I have faced the problem with timezone. I had 3 data sources with different timezones (GMT, CET, CEST). Most confusing thing was, that I didn’t know, how to deal with summer time. But why did I have the data ... [Read more...]

Transaction cost analysis and pre-trade analysis

April 20, 2011 | Dzidorius Martinaitis

Transaction cost analysis (TCA) is the framework to achieve best execution in trading context. TCA can be split into three groups: pre-trade analysis, intraday analysis, and post-trade measurement. Pre-trade analysis allows us to get insight about the future volatility of the price, forecast intra-day and daily volumes, market impact. It ... [Read more...]

Book: ggplot2 by Hadley Wickham

April 4, 2011 | Dzidorius Martinaitis

All my recent plots are built using ggplot2 package. I don’t know if my dear readers have noticed the difference, but from my point of view, ggplot2 allows to create nice looking and aesthetics plots. I was using this package before, but the real boost came after reading this ... [Read more...]

Correlation network

March 22, 2011 | Dzidorius Martinaitis

I came up with an idea to draw correlation network to get a grasp about relationship between a list of stocks. An alternative way to show correlation matrix would be head map, which can have limitations with big matrices (__100). Unfortunately, ggplot2 package doesn’t have a easy way to draw ... [Read more...]

Tick data retrieval

January 31, 2011 | Dzidorius Martinaitis

I just published Java based code to pull tick data from Interactive Brokers. There are thousands tools to get tick data from IB, but I had one feature in mind. You can get maximum 50 quotes per second from Interactive Brokers (its IB limitation for TWS API) . Imagine a situation, when ... [Read more...]

Interesting volatility measurement, part 2

January 21, 2011 | Dzidorius Martinaitis

A few weeks ago I have mentioned about an interesting volatility prediction. It is based on two periods of historical volatility (standard deviation). The remaining question was – does it really works? I could not give the answer, because I didn’t have VIX futures data at that time. Later on, ...

[Read more...]

Seasonal pair trading

January 10, 2011 | Dzidorius Martinaitis

quanttrader.info is a good quantitative repository, where I found an idea about seasonal spreads play. The idea of seasonal pair trading differs from pairs trading in a way, that it doesn’t try to find deviation from the spread’s mean, but it looks at seasonal spread patterns. In ...

[Read more...]

High readings of VIX index during 2 days

December 28, 2010 | Dzidorius Martinaitis

During last two sessions (December 23th and 27th), VIX index posted returns (close to close) above 6 %. My question is – what return can we expect next day after such event? As you can see from the graph above, expected return is positive. During 1995-2010 were 53 such events and mean return was 1.02 % [...]