@article {Phoa1, author = {Wesley Phoa}, editor = {Goyal, Gauri}, title = {Practical Applications of Portfolio Concentration and the Geometry of Co-Movement}, volume = {1}, number = {2}, pages = {1--3}, year = {2013}, doi = {10.3905/pa.2013.1.2.014}, publisher = {Institutional Investor Journals Umbrella}, abstract = {Portfolio Concentration and the Geometry of Co-Movement Wesley Phoa Imagine a new visually appealing, intuitive tool for institutional portfolio managers to understand the changing correlations between stocks over time, so they can limit concentration risk.This Practical Applications report shows how Wesley Phoa, author of Portfolio Concentration and the Geometry of Co-Movement , achieved this using a diffusion map method and 3-D gaming technology to visualize correlations of S\&P 500 and S\&P 100 stocks.{\textquotedblleft}A lot of equity managers are not very quantitative, {\textquotedblright} he states in an interview for this report. Phoa set out to find a visual way of representing a mass of information about stock correlations that was both easy to understand and had precise quantitative meaning in its representations.The result is a visually compelling and robust way of looking at correlations between stocks and stock sectors.Phoa is Senior Vice President at The Capital Group Companies in Los Angeles. His article appeared in the Summer 2013 issue of The Journal of Portfolio Management .}, issn = {2329-0196}, URL = {https://pa.pm-research.com/content/1/2/1.14}, eprint = {https://pa.pm-research.com/content/1/2/1.14.full.pdf}, journal = {Practical Applications} }