Carl Icahn, a billionaire investor, speaks during the World

UNITED STATES – OCTOBER 11: Carl Icahn, a billionaire investor, speaks during the World Business Forum in New York, U.S., on Thursday, Oct. 11, 2007. Icahn said he was concerned that stocks may be reaching a peak, as risks to the U.S. economy remain after the Federal Reserve’s Sept. 18 rate cut. (Photo by Chip East/Bloomberg via Getty Images)