You have the option of rearranging. your 401k investments where you can choose to invest in individual companies instead of the grab bag fund where the managers invest in a little bit, parceled out to many companies where they give equal weight to investing in Intel, Dell, Microsoft and Apple. Which is a horrible deal because Apple, for example, has outperform those three companies by a wide margin over the last 20 years.
Note: you have to go out of your way. to make this happen. Most funds prefer to dump everything together, so they don’t have to make individual tough decisions.