Previously we introduced Singular Spectrum Analysis SSA and its multivariate extension MSSA as a powerful tool for cleaning data. Here we compare MSSA with the data filling algorithm M-REM (Multivariate Regularized Expectation Maximization). We compare theoretical methodology, numerical...

Data cleaning in the real world has to cope with new data arriving (or failing to arrive) as time passes, and which may be bad data. We illustrate MSSA data cleaning with a real-time historical simulation on some problematic data. The example also serves to determine some MSSA algorithm...

This paper introduces a powerful method for detecting and fixing unphysical spikes in time series. The method utilizes Multiple Singular Spectrum Analysis (MSSA) to define local market trends used to identify outlier data spikes that are not caused by market movements, and then effectively...

The financial crisis of 2008 had many putative causes. Psychology was an important driver for human decisions underlying these causes. However, quantitative financial models have no “knobs” to dial psychology parameters, and so arguably cannot possibly cope with financial crises. We have no...

We introduce advanced idiosyncratic risk (“AI-Risk”), a parsimonious correlated residual correction to a predictive stress CAPM-like factor model, aimed to get more accurate stock-stock correlations. We find that AI-Risk can be significant for stock portfolios. Inclusion of AI-Risk gives a...

We show that VAR calculation speedup of an order of magnitude can be obtained using Smart Monte Carlo with a sophisticated interpolator. As a byproduct, we give some encouraging numerical results for evaluating N-dimensional Gaussian integrals without doing any integrals at all

Path integrals are useful and general. Here we show how to calculate Greeks using path integrals. In particular we exhibit the solution to an otherwise troublesome calculation – gamma for a digital option. A subsequent paper will present more detail

We construct “Hybrid Value at Risk” (HYVAR) that is an arbitrary mixture of Historical VAR and Monte Carlo VAR. The procedure is capable of retaining both the correlation matrix of the original time series and also jumps/‘fat tails'. For this reason HYVAR provides more realistic scenarios,...

A common scenario risk analysis employs a multiple factor model with assumed changes in the factors to obtain changes in non-factor variables. This analysis is sometimes designated as a “predictive stress scenario”. We choose to designate the factor model as a multifactor “CAPM” model,...

This paper contains new results for helping to understand financial crises. First, we present a new model for obtaining the probability of equity crises within one year in advance, and we test it. Second and separately, various markets already in crises appear quantitatively related to a theory...