The possibility that verbal hostilities between the United States and North Korea could trigger geopolitical conflict had investors on the run last week.

Since the start of the bull market in 2009, U.S. companies have been buying their own stock. Stock buybacks peaked during the first three quarters of 2016 and have dropped off sharply since then.

Gross domestic product (GDP) grew by 2.6 percent during the period, according to the advance estimate for economic growth. This was an improvement over growth from January through March, when GDP increased by 1.2 percent.

Do we have central banks to thank ? Low interest rates, accommodative monetary policy, and improving economic growth have helped stock markets around the world reach record highs, reports Barron’s.

The main force behind the rally was the dovish performance by Federal Reserve Chair Janet Yellen in Congress on Wednesday and Thursday when she reiterated that rate hikes would most likely be gradual.