Pimco, home to the world's largest bond fund run by co-founder Bill Gross, upgraded its assessment on U.S. economic growth today, saying it expects it to run between 2.5 percent and 3 percent in 2014, from 2.25 and 2.75 percent.

In its global economic outlook, Pimco said its baseline expectation for 2.5 percent to 3 percent real growth in the United States stems from "trends toward growth and spending in the consumer, corporate and public sectors."

In December, Pacific Investment Management Co, better known as Pimco, said that the firm expected U.S. economic growth to run between 2.25 and 2.75 percent in 2014.

"The global economy will likely experience steady, broad-based growth in 2014 thanks in no small part to the extraordinary expansion in central bank balance sheets in 2013," the Pimco research outlook report said. "Rising asset prices in combination with fading near-term fiscal uncertainties will drive global aggregate demand growth forward, adding stability to what has thus far been an on-again, off-again global recovery from the financial crisis of 2008."