The Dow Jones Industrial Average topped the 40,000-point mark for the first time during trading on the New York Stock Exchange on Thursday.

Carl Weinberg, Chief Economist at High Frequency Economics, says that surprisingly strong US corporate profits are behind the Dow's record intraday high.

He said, "We have very, very good expectations that inflation is falling, and even though there have been some bumps along that road, the path toward regaining price stability still looks pretty clearly ahead of us. And while we are waiting for the US Federal Reserve to be sure, we are pretty confident that they will at some point soon be cutting interest rates."

However, he warned that the US economy may grow too fast: "Some exogenous elements suddenly make the US economy grow so fast, that prices do accelerate, and then the Fed would have to reverse course on easing and start talking about tightening. To me, that's the more dangerous risk that we face right now."

Weinberg believes price movements should be closely watched.