The first four weeks of October 2018 have seen big drops in stock prices across the globe, and as in any market correction, the question that you face as an investor is what, if anything, you should be doing in response. I feel the urge to react, but I know that if I do so, I can put my portfolio at risk. I go through a four step process, starting with a hitting of the pause button, following up with using the data to assess the damage and a check of the fundamentals, before acting. The bottom line is that none of the offered explanations for the stock rout hold. Slides: http://people.stern.nyu.edu/adamodar/pdfiles/blog/OctoberSurprise.pdf