Analysis-US stocks may not be in a bubble, but a pullback could be near

Some market participants believe the relentless U.S. stock rally is poised for a breather, even if it remains unclear whether equities are in a bubble or a strong bull run. The benchmark S&P 500 index is up over 25% in the last five months, a phenomenon that has occurred just 10 times since the 1930s, according to BofA Global Research. In an advance led by stunning gains in chipmaker Nvidia, the S&P has already made 16 record highs this year, the most in any first quarter since 1945, CFRA Research data showed.