Unless you actually need the money now, you're better off just holding on and riding the wave. Many studies show that buy-and-hold outperforms market timing >69% of the time.
Think about it this way - let's say you sell today and there is a 10% correction immediately after that. If you sell and pay $9k in taxes, you're left with $91k. If you hold and eat a 10% dip, you're sitting at $90k... virtually identical scenarios. On the other hand, if you sell now and the market goes up another 10%, you're talking about the difference between $91k and $110k and you're going to be kicking yourself.
Couple that with the fact that the market tends to rise over time, and holding starts to look even better. Short term losses and gains are almost impossible to predict, but macro performance in the long- to very long-term is actually pretty easy: the market's going to go up, and the longer you hold on, the better your odds are of capturing that return.
Here's another example. Let's say you're 35-40 right now and don't need the money right away, so you're looking at a 30-year horizon for your investments. What are the odds that the market will rise over the course of those 30 years? Obviously there aren't any guarantees about the future, but if you use the past as a guide, you would say virtually 100%. If you look at the performance of the S&P 500 over the past century, and try to pick the absolute worst time to invest (at the market peak immediately prior to the Great Depression) with a 30-year horizon, you're still looking at about an 8% annual return over that time period.
If you let short-term fear and emotions rule out, you might get lucky here and there, but the odds aren't in your favor when you're betting against that kind of long-term macroeconomic trend. Hold on long enough though, and you're almost guaranteed to win.