Investors and their advisors have enjoyed a pretty good relationship over the past few years, helped by a steady bull market that has seen investors' portfolios fatten. However, will that good feeling continue if the markets that are currently flirting with record highs reverse course? Intuitively, you might expect that clients are more likely to take legal action against their advisors when the markets head south. But is that intuition accurate? A look at the numbers says it's spot on. Data over the past 10 years from the NASD shows that the number of arbitration cases filed hit a peak of 8,945 in 2003, following the S&P 500's last market bottom in October 2002, while a broader comparison of the performance of the S&P 500 and the number of arbitration cases filed with NASD over that time shows a clear correlation between market performance and ticked-off clients.