This is really weird. My 401k is through fidelity, who gave me a bunch of different choices -- buy the tech index, buy the emerging markets index, etc, etc. I bought vanguard general. I know the exact composition of the thing, not that it matters, because it's the s&p. No one "manages" it. Course it's not going anywhere, but I don't really mind at the moment.
Check the fees. My wife had a 'managed' and 'unmanaged' 401k through Prudential and both of them were charging more than a percent. Lookin' at a friend's Fidelity 401k right now (he doesn't understand this shit so he gave it to me to tell him what to do). They talked him into a T Rowe Price mutual fund that charges 1%. One of the tricky things about funds is that yes - they tell you what's in there but not with a lot of specificity. "The S&P 500" - well, what does that mean? In a mutual fund, that means a synthetic blend of trades that model the S&P within whatever error bars they have buried underneath the fine print. With Vanguard it's probably very specific; right now, they're listing all their shit as of a week ago. With Fidelity? That's a quarterly prospectus. ETFs have, buried deep somewhere on the Internet, their daily .csv of holdings; I've found it for a couple of my etfs a couple times. Funds, managed or otherwise, will tell you that shit four times a year and in between, you really have no idea.
Vanguard doesn't really have fees. I think it comes out to $25 a year or something if you add the various fine print up, but you can get a chunk of that back if you sign up for paperless everything. It's been a while since I looked closely. The variable part is tiny. As far as composition, usually an index fund owns pretty much everything you've heard of. A "passive" plan doesn't change much. Vanguard's one of the best. I just bought most of a condo, so I'm certainly not banking on the stock market for my retirement. francopoli details elsewhere why that's nuts.
1) You're with Fidelity. The fact that you're paying little in fees for Vanguard funds is a function of Vanguard, not Fidelity. Again, check the fees Fidelity is making. 2) Index funds do not "own pretty much everything you've heard of." Index funds track indices and even two S&P funds from two different companies have different compositions and different fee structures. 3) Don't talk to me like I'm an idiot. 4) It's entirely possible that even paid in full, you don't own your condo. You own a legal share of a 99-year-lease. That's the mechanism by which many condominium associations enforce their rules.