This link opens a PDF article written by Weston Wellington of DFA which quantifies the behavior of markets after 5% and 10% market corrections. It's a brief article, written for the general public, complete and backed by sound data as is always the case with material from DFA. They've made it easy to digest, brief and provided a reasonable suggested conclusion:"Investors who accept dramatic price fluctuations as a characteristic of liquid markets may have a distinct advantage over those who are easily frightened or confused by day-to-day events and are more likely to achieve long run investing success."I think the words "may have" are used purposefully to understate so that this article could be shared with the public.VERY IMPORTANT NOTE: If you are reading financial media from any source which constantly sensationalize, then achieving Mr. Wellington's conclusion above will be extremely difficult!!!The article gives more detail that I encourage you to review. Here's a subset of the data without all the fine print of how the data was developed.10% declines and subsequent 12 monthsUS Large Cap (1/1926 - 6/2015) (happened 28 times) annualized 12 month return after: 23.56%International Large Cap (2/2001 - 6/2015) (happened 9 times) annualized 12 month return after: 24.73%Emerging Markets (1/1999 - 6/2015) (happened 15 times) annualized 12 month return after: 42.23%So what is the "to do list". Well, if you are receiving and acting upon prudent advice, then the following approaches should already be in place.Retired and actively accessing a portfolio for some of your living expenses? Then you should have a 2-5 year cash reserves cushion that you access when the market has gone down 10%. Once it recovers then you can access it again, and also gradually replenish your cash reserves. Re-balance your portfolio and with the stocks you will automatically shift more to stocks while they're down. No need to lock in 2-4% return in an annuity.Actively saving for the future? Great - keep going! You're getting a bargain on your stock purchases! Save even more if you can. Re-balance your portfolio and with the stocks down you will automatically shift more from bonds to stocks while they're down.Have a lump sum cash that you wish to invest? Invest at least some, if not all, immediately. This is a guessing game since we cannot accurately predict market bottoms. (No one can predict it accurately.) If the market down turn has been sudden and severe, then you probably should invest all of it immediately. If it seems like the down environment is lingering, then you can set up an automatic purchase plan over a period of time. It truly is a guess. If the market shows signs of recovery then invest the rest if you haven't already. Don't lok back and second guess your decision enter the market. As you double, triple and quadruple your money over the long term, how you entered the market will be forgotten.