wow you caught me off guard, really interesting question and i think that you should realize that stock market corrections really aren't an issue if you remain focused on the long-term with retirement as your goal. The only people who should be worried when corrections roll around are those who've geared their trading around the short-term. Maintaining a long-term view has been the smartest way to invest in cryptocurrency since 2009 and it also happens to be a recipe for a good night's sleep.
Now to answer your question to where that money goes you have to ask yourself how did all that money got there in the first place. From people that invested in and the same people are the ones that making the corrections happen just by selling big amounts in once. I hope i was helpful :)