As the market gyrates it may be difficult to keep focus on saving and investing for retirement. Keep disciplined.
Try the Lazy Portfolios for retirement funds. Low cost, excellent diversification, outperformance. My favorite is the Margaritaville selection consisting of three mutual funds with domestic stocks, international stocks and government bonds.
Or the Permanent Portfolio which allocates funds among five asset classes thus giving it very steady performance in good and bad markets. This replicates the Harvard and Yale endowments.
One recommendation would be to put half allotment into the Margaritaville funds, and the other half in Permanent Fund. Any additional funds could be dollar-cost averaged into the four separate mutual funds.