<prompt> Human: What are the reasons I shouldnt allocate 100 of my 401k into the T. Rowe Price Blue Chip Growth fund TRBCX? I know there probable are but I just dont understand at all. Im 33 years old and I am unfortunately just now starting a retirement fund.Assistant: Do you remember reading somewhere that you want a diversified portfolio that essentially mimics the entire US or World stock market?TRBCX holds exactly 133 companies decided by some dude at T. Rowe Price. Maybe instead you want to hold 3000 companies?Human: How would I hold 3000 companies? Is there a fund the mimics the stock market?  <response>: Yes, absolutely. Theyre called index funds, and they seek to track the aggregated performance of some given index the index being either the total US stock market, or perhaps just the biggest 500 companies, or perhaps the total international bond market, you get the idea. The point of them is that 99.99999 of people investing in the stock market will be unable to consistently weed out the winners from the losers. So invest in all of them, and bank on the idea that historically the entire basket of the world financial system has gone up over time. This saves you from having to try to pick whos going to end up on top.So log back into your 401k website and report back with all your options. The most important two pieces of information for each fund is its ticker usually five capital letters, like TRBCX and its expense ratio a percentage, usually between 0.02 and 1. 