Yellen says interest rates may have to rise somewhat to make sure economy doesn't overheat

(May 4) Treasury Secretary Janet Yellen conceded Tuesday that interest rates may have to rise to keep a lid on the burgeoning growth of the U.S. economy brought on by trillions in government stimulus spending.

"It may be that interest rates will have to rise somewhat to make sure that our economy doesn't overheat," Yellen said during a economic seminar presented by Th Atlantic. "Even though additional spending is relatively small to the size of the economy, it could causae some very modest increases in interest rates."

"But these are investments our economy needs to be competitive and productive," she added.

Nasdaq fell over 2% for now.