You are thinking about investing backwards.
It seems like you started off well. Choosing 5 funds probably means you diversified. Of course, you could have chosen 5 nearly identical funds, but I will assume you chose 5 completely different ones. If so, good start.
But, here is the key: you must KEEP it diversified. Do not be tempted to sell the poorly performing funds and buy this well performing fund. Why? Think it through. If you sell the poorly performing funds, you are selling low. Then if you buy that Emerging Market fund, you are buying high. You are asking us if you should sell low, buy high. Now, think back at the cardinal rule of investing: buy low, sell high. Your suggestion is to do the exact opposite.
In the short term, you MAY be better off selling low and buying high. But in the long term, that Emerging Market fund will eventually do poorly and the other funds will do well. What happens then? All (or lots) of your eggs are in that one poorly performing basket. Suddenly, you watch your investments go to the crapper. That isn't what you want to do.
This may be hard, but what you want to do is to rebalance your portfolio. Do it maybe once a year. When you rebalance, you make sure it is diversified again. This means selling a bit of the funds that skyrocketed (sell high), and use that money to buy a bit of the funds that did poorly (buy low). Do this and when the Emerging Market fund tanks, you won't have much of it. And when your other 4 funds soar, you will have lots of them.
Note 1: If any of your other 4 funds ALWAYS performs poorly, get out of it. No fund will always do well, but some funds will always suck. If you find you are in one that always sucks (high fees, low short term returns, and low long term returns), then sell it and buy a fund that is doing better.
Note 2: You are really playing the dollar. As the dollar falls in value, foreign stocks appear to go up, even if they didn't move at all. For example, if you have something foreign worth $1000, and then the dollar falls 10%, you can now sell it for $1100, even if in other currencies the value of that item didn't change. The US dollar has fallen ~15% in the last year and a half. Thus, most of the reason your Emerging Market fund went up 20% was because of the dollar falling in value, not because those funds are doing well. If the dollar goes back up OR if the foreign stocks fall, your fund will come back down.
Projections are nearly impossible. Short term, I think you are good to be in that Emerging Market fund. Short term, you may likely do well to have more of it. But, the dollar will eventually come back up, or those foreign stocks will eventually do poorly. When that happens is anybody's guess. So, long term, I wouldn't want too much of it. You do want some of it for diversification, but not too much.
