That doesn't really work very easily. Index funds can operate the way they do because a lot of people buy into the same fund. When you buy and sell shares in t

That doesn't really work very easily. Index funds can operate the way they do because a lot of people buy into the same fund. When you buy and sell shares in the "real" market, you do so in whole numbers. If you're going to construct an index fund just for you, the smallest amount of any stock you can buy is 1, so you'd need an enormous capital investment: if you want e.g. 1% of your fund to be Google (currently trading at $934), and assuming all the share prices work out just right -- in practice, they won't -- your smallest unit of investment would be $93,400. In practice, the closest approximation of what you describe is just having a passive portfolio: pick a bunch of stocks, buy them, and then don't look at them again.