Goldman Sachs told clients President Donald Trump's agenda may ultimately disappoint investors because of a less ambitious tax cut, increased trade protectionism and implementation delays.
The S&P 500 is up 7 percent since Nov. 8 through Friday.
"Following the election, the positive shift in sentiment among investors, business, and consumers suggested that the probability of tax cuts and easier regulation was seen to be higher than the probability of meaningful restrictions to trade and immigration," economist Alec Phillips wrote in a note to clients Friday. "One month into the year, the balance of risks is somewhat less positive in our view."
The economist gave three reasons why the market may be overly optimistic: