I focus only on two mutual funds (anyway no much choice in company’s 401K plan), one mid-cap fund ACRNX which seeks capital growth, and one income fund PTTRX which seeks consistent monthly income. If you plot a long-term chart of both funds, you will see ACRNX fund up and down over the time, but PTTRX is relative stable even when the general market was crashed.
So my strategy is simple.
When general market is in the uptrend, I want all my balance in ACRNX fund; and when general market is in down trend, I want all of my balance in PTTRX fund, in which I can still make money even in the market down-turn.
But in reality, there are lot of times when general market has no clear direction. In that case, I change the percentage hold in each fund based on my own perception to the market.
For example, I am all out of ACRNX fund, and in PTTRX right now, because I think general market will be in down turn in the near future. I might be wrong for a few percentage gain, but I still have income from PTTRX fund. My big #1 goal in my 401k investment is to avoid risk of market crash only once. If I can achieve that, I would be very successful.