Quantitative investing based on computer formulas and trading by machines directly are dominating the equity markets, CNBC reported, citing a JPMorgan research report.

“While fundamental narratives explaining the price action abound, the majority of equity investors today don’t buy or sell stocks based on stock specific fundamentals,” Marko Kolanovic, global head of quantitative and derivatives research at JPMorgan, said in a Tuesday note to clients.

Kolanovic estimates “fundamental discretionary traders” account for only about 10 percent of trading volume in stocks. Passive and quantitative investing accounts for about 60 percent, more than double the share a decade ago, he said.

In the weeks heading into May 17, Kolanovic said funds bought bonds and bond proxies, sending low volatility stocks and large growth stocks higher. Value, high beta and smaller stocks began falling in a rotation labeled “an unwind of the ‘Trump reflation’ trade,” Kolanovic said.

Derivatives, quant fund flows, central bank policy and political developments have contributed to low market volatility, Kolanovic said. Moreover, he said, “big data strategies are increasingly challenging traditional fundamental investing and will be a catalyst for changes in the years to come.”