<prompt> Human: Right now I have all of my 401k contributions going to the Vanguard 500 index fund, primarily because the expense ratio. .05 instead of 1 or 1.5 I figure with zero other work Im automatically getting a point or more higher return than the managed funds my company offers.When I discuss this with people theyre all surprised I have all my money in the one fund. But as far as I was thinking its automatically diversified by the pure virtue of being a fund rather than an individual stock.Am I silly to pour everything into the one index fund my company offers?For context I am 31 and just started contributing last year, so its a pretty small amount of money were talking about here...so far...  <response>: Well, your eggs are actually in 500 baskets from one perspective, one basket the stock market from another.Since its 401k money and youre presumably years from needing it, thats the right place to be.I keep recommending reading the first maybe half dozen of the stock series over here: 