S&P 500 Movers: PSKY, GNRC

In early trading on Thursday, shares of Generac Holdings topped the list of the day's best performing components of the S&P 500 index, trading up 24.1%. Year to date, Generac Holdings registers a 59.4% gain. And the worst performing S&P 500 component thus far on the day is Paramount Skydance, trading down 2.9%. Paramount Skydance is lower by about 19.3% looking at the year to date performance. Two other components making moves today are Salesforce, trading down 2.7%, and Ciena, trading up 7.5% on the day. VIDEO: S&P 500 Movers: PSKY, GNRC And the worst performing S&P 500 component thus far on the day is Paramount Skydance, trading down 2.9%. Paramount Skydance is lower by about 19.3% looking at the year to date performance.