So much for a sleepy second half... With a possible exit by Greece from the euro, Puerto Rico's governor saying it's unable to pay its debts and Chinese stocks in a bear market, the world for investors changed over a single weekend. "Now that Greece has been caught and Puerto Rico has confessed, all the other criminals are in jeopardy," wrote Brian Kelly of hedge fund BKCM. "I don't know if we are at the beginning of a systemic debt domino effect, but if we are, I would expect to see multiple confessions over the next six-12 months." The CBOE Volatility Index —the market's fear gauge—lost a quarter of its value until last week, when it started to creep higher into the weekend. The measure was up more than 15 percent in early trading Monday. So if we're in for period of sustained volatility in the second half of the year, here's how to batten down the hatches. CNBC Pro, using quantitative investing tool Kensho, looked at all the five-day periods during the past decade when volatility surged. Specifically, we studied the more than 70 periods when the VIX jumped over 20 percent in a week's time and found which exchange-traded funds moved higher during that time span and by how much. This should give a window into what to buy this week and beyond if we are in fact in for a volatile rest of 2015. ETFs that invest in government bonds and corporate bonds are the top places to hide out, and even profit, when volatility spikes and the risk-off trade becomes the norm. These securities should also benefit if the Federal Reserve uses Greece as an excuse to push back rate hikes from its September meeting. Read More Only one person on Street says buy these stocks As far as stocks, no individual equity in the S & P 500 was consistently higher during these weeks when volatility surged. However, if rates are headed lower on a Fed delay and a flight to quality into bonds, that should boost utility stocks, whose hefty dividends offer a safe haven for investors. Those shares were higher Monday, led by Public Service Enterprise Group , Consolidated Edison and American Electric Power . Disclosure: NBCUniversal, parent of CNBC, is a minority investor in Kensho.
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