London (CNN Business) Happy Tuesday. A version of this story first appeared in CNN Business' Before the Bell newsletter. Not a subscriber? You can sign up right here.

The S&P 500 notched a new closing record on Monday, jumping above 3,039 as hopes for progress on a US-China trade deal sent markets higher.

But fresh highs raise the question: How much longer can the bull market for US stocks go on?

UBS, in a report out Monday, said it believes the US business cycle has transitioned to its late stage, as characterized by decelerating economic growth and Fed monetary policy that's "roughly neutral." The bank reduced the proportion of stocks it recommends wealthy clients hold in their portfolios earlier this year.

From UBS senior economist Brian Rose: "Last year, our main concern was that the economy would overheat, forcing the Federal Reserve to tighten monetary policy and causing the cycle to end. More recently, growth has slowed and the Fed has been cutting rates. The main risk now appears to be that the economy will simply continue slowing until a recession begins."

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