– North Korea summit between Washington and Pyongyang could be the spark, says Wien –
By Mark DeCambre, MarketWatch 
Blackstone's Byron Wien says investors enjoying a recent rally in the stock market shouldn't get too comfortable, even if the Wall Street veteran is optimistic about the domestic economy over the next two or three years.
"My feeling is that there's something lurking out there, Carl, that is going to upset the market and it's probably a geopolitical event. Maybe the upcoming North Korea summit," Wien said during a CNBC interview with anchor Carl Quintanilla Thursday morning.
A vice chairman of Blackstone Group L.P.'s private wealth group, Wien's comments come as the Cboe Volatility Index one measure of Wall Street fear that tends to fall as stocks rally and surge as they tumble, hit its lowest level since late January.
The so-called VIX, which reflects bullish and bearish options bullish and bearish options bets on the S&P 500 had been mostly dormant in 2017, until jumping by 116%, the most in its history back in early February, as the S&P 500 and the Dow Jones Industrial Average began a retreat into correction territory. A correction is usually defined as a drop of at least 10% from a recent peak.
Although the Nasdaq Composite Index on Thursday was pulling back, the broader market has seen a resurgence in market optimism and decline in volatility underpinned by gains in technology and internet stocks.
Even as Wien thinks that investors shouldn't get too complacent about the possibility of a return to jittery markets that have characterized the recent market regime after the VIX's surge, he thinks the economy is on a firm footing.
"There will be 10% corrections along the way" he told CNBC but said "generally, we are in a period of low volatility because there isn't a recession in sight. My view is the earliest we're gonna have a recession is 2021."
Meanwhile, there will be plenty to knock the stock market around, including-as Wien mentioned-President Donald Trump's planned gathering with North Korean leader Kim Jong Un in coming days. Separately, the market has been sensitive to political developments in Europe, particularly the emergence of antiestablishment parties 5 Star Movement and the League in Italy.
From MarketWatch