NEW YORK, Sept 3 (Reuters) - Investors are girding their portfolios for potential stock market volatility, even as equities hover near fresh highs after logging seven straight months of gains. Utilities (.SPLRCU) are the S&P 500"s best-performing sector so far this quarter with a 10.2% gain. They have been followed by other popular destinations for nervous investors, including real estate and healthcare. In derivatives markets, the gap in price between the front month Cboe Volatility Index futures contract and the VIX index itself (.VIX) is higher than it has been about 85% of the time over the last five years. This suggests some investors expect the calm in stocks to give way to more pronounced price swings in the coming weeks and months. Meanwhile, the Japanese yen and Swiss franc - viewed as havens during uncertain times - have outperformed most G10 currencies this quarter. "It"s been a year of positive market returns, but it"s a bull market which has pretty defensive undertones," said Saira Malik, head of global equities at money manager Nuveen Investments. The demand for downside protection illustrates a conundrum that has bedeviled investors at various times during the market"s post-pandemic surge. Ultra-low yields on fixed income have left few alternatives to equities, and betting against stocks has been a disastrous strategy in the last year-and-a-half. Stocks demonstrated their resilience on Friday, when the S&P appeared to shrug off a big miss on August U.S. employment data, as some market participants bet a weaker economy could undercut the case for the Federal Reserve to unwind its market-supportive easy money policies in coming months. The benchmark index is up 20.4% this year. read more At the same time, many have grown antsy in a market that has gone 292 calendar days without a decline of 5% or more, nearly three times the average since World War II, according to data from CFRA"s Sam Stovall. Rising valuations, ebbing economic growth and signs of speculative excess have only added to their concerns. "It"s been a wonderful ride for U.S. equities ... but moving forward we think it is going to be a little bit of a different picture," said David Grecsek, managing director in investment strategy and research and partner at Aspiriant, which manages about $14.5 billion. Concerns over equity valuations have prompted Grecsek to take profits in some of his equity positions and shift some money into non-U.S. stocks, including emerging markets. The S&P 500"s price-to-earnings ratio on a forward 12-month basis stands at 21.3, a 35% premium to its 20-year average, according to Refinitiv Datastream. Investors next week will be keeping an eye on quarterly results from video game retailer GameStop Corp(GME.N), whose wild ride this year put a spotlight on retail investors" mania for so-called meme stocks that some say is one sign of irrational exuberance in markets. On the macro front, next week"s U.S. August producer price index data could provide some clues on how inflation is shaping up after July showed the largest annual increase in over a decade. read more With the Delta variant of the coronavirus continuing hindering growth, "a lot of investors are seeing maybe some headwinds and positioning more defensively," said Ross Mayfield, investment strategist at Baird in Louisville, Kentucky. Analysts at Morgan Stanley in the past week cut their view on third-quarter U.S. gross domestic product to a gain of 2.9%, from a 6.5% increase. Some of the flows into defensive sectors may have more to do with investors hunting for yield rather than worries over an impending market crash. The S&P 500 Utilities index (.SPLRCU)sports a yield of about 3%, while the yield on the benchmark U.S. 10-year Treasury note stood at around 1.33% on Friday. "The wall of worry does loom on the horizon ... but the main reason defensive (stocks) are holding up relatively well is because of the income stream attached to them," said Terry Sandven, chief equity strategist at U.S. Bank Wealth Management. Sandven, Nuveen"s Malik and Baird"s Mayfield all remain bullish on stocks, despite the market"s defensive undertone. History may be on their side: the S&P has held on to a double-digit annual gain in eight of the last 10 years that it rose by 20% or more in the period from January through August, as it has in 2021, according to a report from BofA Global Research. The exceptions were 1929 and 1987, which were both marked by historic market crashes.