With U.S. stocks doing a stutter-step after a five-year bull run, a shift into low-volatility funds might give you a little more traction if the market retrenches.

Low or "minimum" volatility funds have become more popular since the 2008 meltdown. They buy mostly defensive stocks with high dividends and modest price variations, and represent an $11 billion market for moderately risk-averse investors.

The most popular fund in this category, the PowerShares S&P 500 Low-Volatility ETF (SPLV), holds more than $3 billion in assets. It owns brand-name stocks like McDonald's Corp and Johnson & Johnson, along with lesser-known companies like Sigma-Aldrich Corp.

The fund, which charges 0.25 percent for annual management expenses, was up 15 percent for the year ended February 20.

A similar fund is the iShares MSCI USA Minimum Volatility ETF (USMV), which with about $2.5 billion in assets is a runner-up in terms of size in this group. It holds nearly half of its portfolio in consumer defensive, healthcare and financial services stocks like AT&T Inc, Wal-Mart Stores Inc and United Parcel Service Inc.

The fund charges slightly less in annual expenses at 0.15 percent, and gained nearly 18 percent in the year through February 20. But both it and the PowerShares ETF are lagging the Standard & Poor's 500 stock index, which is up 22 percent for that period.

Although it is too early to tell, low-volatility funds might have a distinct advantage if the bull cycle has reached or surpassed its peak. If corporate earnings falter or global economies slow, the market may tilt toward value and dividend-rich stocks.

Despite the desire to time the top of a bull market, it is tough to make an exit from growth stocks into high-dividend shares. Market peaks are notoriously difficult to discern.

The most pressing question for a long-term investor is whether to tilt more toward value than growth. Until this year, growth stocks have had their run of the roost, but value may dominate if fear stalks the market.

It is typical for low-volatility funds to bulk up on boring, dividend-rich sectors like consumer durable, healthcare and utilities.