The key for 401K success is steady growth with controlled risk. Individual stock may give you a quick gain if you concentrate and if you hit it right, but can let you lose shirts (or skirts haha) if you hit it wrong.
- Have broader EFTs (VTI, VOO, VB, VO, VWO/EEM...) as core holdings
- Use sector ETFs to tune according to market: Vanguard & Fidelity have lots of fee-free ETFs. (If you have employer sponsored brokerage, you may have to pay transaction fee).
Housing: XHB, ITB, VNQ, ...
Materials: ...(there are a lot)
Energy: VDE, OIH,....
Check out the Vanguard & Fidelity sites.
Fidelity has a great ETF chart/mapping graphics tool.