There's a yawning chasm between the real U.S. economy and how markets are behaving, and the media is to blame, according to J.P. Morgan Chase's top quant Marko Kolanovic.

Strong corporate profit growth and consumer spending signal that the economic expansion isn't about to end, in contrast to future price-earnings estimates and institutional equity holding levels near five-year lows, Kolanovic wrote Friday in a 2019 outlook note. He has a 3,100 target on the S&P 500, which would be a 17 percent increase from current levels.

"Positive GDP and earnings are 'reality,' which is currently starkly disconnected from equity sentiment, valuation, and positioning," Kolanovic said in the note.

Despite the positive backdrop, markets have been pummeled amid concerns about U.S.-China trade tensions and slowing economies worldwide. This week alone the major indexes were all down more than 3 percent, and the moves have been violent. One reason attributed to the declines has been the reversal of central banks' programs that bought trillions of dollars of assets after the financial crisis.