The economic good times will roll on through the Fall and investors should buy any serious market dips, especially the banks, said Talley Leger, investment strategist at OppenheimerFunds.

"Welcome to the Great Moderation 2.0," said Leger. "That's what we've dubbed the extremely favorable mix of conditions that characterize the current environment: supportive monetary policy, low interest rates, subdued inflation, and an economy that shows no signs of overheating."

In his view, this equity market rally may be one of the most unloved of our time. Even the vote to leave the European Union and the associated political instability in the UK -- the fifth largest economy of the world -- wasn't enough to derail the ongoing economic expansion.

Leger said the U.S. has three factors working in its favor -- limited exposure to the UK at just 3.1% of total trade, consumers well supported with average hourly earnings growth of 2.6% year over year and a recovering manufacturing sector as evidenced by the ISM Manufacturing PMI at 52.6.

Leger said the financial sector is currently the most promising because it has been unloved and under-owned throughout the cycle. He points out that U.S. commercial banks have pumped out record profits, as reported by the Federal Deposit Insurance Corp.

As to the future of interest rates, Leger does not have a specific or formal target for the yield on the 10-year Treasury. Still, he expects rates to stay subdued for the foreseeable future "as long as the Fed has learned this valuable lesson and keeps rates low."

"Our view is that this could potentially be the longest business cycle on record," said Leger. "It's already over seven years long. That compares to the 1990s, which was over 10 years. If we get that great Moderation 2.0 we think the upside for stocks is good right here."