You have already picked excellent fund companies. Of the three you mentioned, Fidelity and Vanguard have an enormous variety of mutual funds to choose from (T.Rowe Price has excellent funds, but far fewer in variety.) Also, Vanguard has been and continues to be the fund company with the lowest fees overall, although Fidelity is certainly trying to compete hard there as well.

Since IRA money is for your retirement, and thus for the long-term, you should not be too conservative with it (no CDs, for example). This argues for a high % of stocks or even 100% stock fund (depending on any other investments you may have, that you didn’t mention).

Shana’s suggestion of one of the target retirement funds is fine. These do tend to be quite conservative but the percentage allocated to stocks drops over time (as you near retirement, which is advisable). The Fidelity and the Vanguard target retirement funds differ in their percentage of stocks for a given retirement date, but are very similar.

But if you have no other stock investments, you could easily go for an S&P 500 index fund, which invests your money in 500 of the biggest US companies. (And thus is well-diversified among US companies.) Alternatively, look for a ‘total market index fund’. Both Fidelity and Vanguard have both of these types of funds.

Whichever you pick, do not judge it by any short-term fluctuations. The market fluctuates, and the ups and downs are important to short-term traders, but considerably less important for your long-term needs.