When investors look back on the most significant event of 2016, it won't be June 23's Brexit vote or Donald Trump's Nov. 8 election victory, or even if the Fed's expected rate hike in December.
Instead, it will be July 11.
That was the day everything changed, at least according to the view of Michael Hartnett, chief investment strategist at Bank of America Merrill Lynch.
On that day, longer-term bond yields hit what Hartnett and a number of other market experts believe was a multidecade low, not expected to be seen again anytime soon.
The move was sparked by expectations that aggressive central bank monetary policy was about to be replaced by fiscal policy measures aimed at goosing the world's economy through big spending.
For investors, that means the end of a generational bond bull market and the beginning of a new regime.
"That day was the day that the greatest bull market ever in the bond market ended. Since then, yields have been rising. That without a doubt is the biggest event of 2016," Hartnett said Wednesday at BofAML's annual outlook for the year ahead. "Everyone was positioned for that to continue."