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Portfolio Probing

The ultimate aim of the Portfolio Probing blog is to help make fund management more effective, to make savings safer through better tools and better methods. Patrick Burns, the founder of Burns Statistics, offers a unique mix of experience in quantitative finance, statistics, computing and writing.

Elsewhere in the blogosphere this week

Markets Sex and statistics Marginal Revolution had the post Sex and Statistics or Heteroscedasticity is Hot which reports on the OkTrends post The Mathematics of Beauty. The summary is that conditional on their average beauty rating, the women with more variable ratings get more interest.  The post proposes a theory that there is less competition … Continue reading

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The number 1 novice quant mistake

It is ever so easy to make blunders when doing quantitative finance.  Very popular with novices is to analyze prices rather than returns. Regression on the prices When you want returns, you should understand log returns versus simple returns. Here we will be randomly generating our “returns” (with R) and we will act as if … Continue reading

Posted in Quant finance, R language | Tagged , | 26 Comments

Boris The Banker explains efficient markets

Amy Anyone: What is EMH? Boris The Banker: That’s the Efficient Market Hypothesis, or sometimes the Efficient Markets Hypothesis. Amy: What’s that? Boris: It says that all available and relevant information has been taken into account in the price of items in the market — a stock market for example. Amy: Does it have any … Continue reading

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Some market predictions

We look at a few forecasts for the year 2011 that we’ve run across, and compare them with the prediction distributions presented in Revised market prediction distributions. FTSE 100 There is a “range forecast” on an Interactive Investor page of 5350 to 6565.  It isn’t clear (to me at least) what this means, but I … Continue reading

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Revised market prediction distributions

This provides revised plots of the prediction distributions published yesterday.  The previous plots of prediction distributions should be ignored — they are not doing as advertised. We show the prediction distribution of levels of several equity indices (plus oil price) at the end of 2011 assuming nothing happens.  That is, we’ve taken out market trends … Continue reading

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Creating prediction distributions

Here we give details and code for the prediction distributions exhibited in yesterday’s blog post “Tis the season to predict”. [Revision: There was a problem with the plots published in that post.  For corrected plots and an explanation of the error, see Revised market prediction distributions.] Eight years of returns The equity indices use daily … Continue reading

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Tis the season to predict

I predict there will be a lot of predictions of markets for the coming year.  Here is a calibration of such predictions. We show the prediction distribution of levels of several equity indices (plus oil price) at the end of 2011 assuming nothing happens.  That is, we’ve taken out market trends and just left drift … Continue reading

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Blog year 2010 in review

The blog year started in August and consists of 30-something posts.  Here is a summary. Most popular Ideas for World Statistics Day A quant review of “The Quants” by Scott Patterson A tale of two returns The tightrope of the random walk What the hell is a variance matrix? Most under-valued Most read is not … Continue reading

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The tightrope of the random walk

We’re really interested in markets, but we’ll start with a series of coin tosses.  If the coin lands heads, then we go up one; if it lands tails, we go down one. Figure 1: A coin toss path.Figure 1 is the result of one thousand coin flips.  It is a random walk. The R command … Continue reading

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Making science happen

One of the things I’d most like to happen in finance is for a science mindset to take hold. Perhaps this would happen more if society as a whole were more scientifically oriented.  Perhaps society would be more scientifically oriented if schools taught science better. Science in schools The possibility of learning science in school … Continue reading

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