Are markets somehow "broken"? That may sound shrill, but some analysts and investors fret that there are some weird sounds coming out from under the hood of the financial system, clanks and whirrs that should worry us all.

Fears over economic growth are spreading, and investors are pricing in the Federal Reserve cutting interest rates three times this year, beginning next month. And yet, various measures of market volatility are surprisingly subdued.

The Vix index, a popular gauge of Wall Street fear that measures the volatility implied by option prices, has nudged higher since May, and so has its equivalent