S&P 500 doubled its average return under past presidents during Trump's first 3 years

The S&P 500 has had a return of over 50% during President Trump's first three years in office, more than doubling the average return of 23% at the same point in a presidential term since 1928, CNBC reports.

The big picture: The market, which hit record highs across the three major indices, got a sustained lift in 2019 after Federal Reserve Chair Jerome Powell lowered interest rates three times, the first such moves since the end of the financial crisis.

• The big gains under Trump come despite a volatile 2018 that saw the S&P drop 6.2%, thanks to the uncertainty of the U.S.-China trade war.
• And by another market's measure, there were worrying signals: the yield curve inverted this year, a phenomenon in the bond market known to precede recessions.

Of note: The S&P's 28.6% growth during Trump's third year lagged behind former President Barack Obama's 32% during his third year, which came as the economy recovered from the financial crisis.

What to watch: The S&P increases two-thirds of the time in a president's fourth year — with an average gain of 5.2%.

• For Trump, any success will likely depend on how trade talks with China play out — and whether his "phase one" trade deal can hold.
• As part of some of the known terms of that deal, China agreed to buy billions of dollars of U.S. agricultural products and Trump agreed to cancel pending tariff increases.

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