S&P 500 Movers: MKTX, EFX

In early trading on Thursday, shares of Equifax topped the list of the day's best performing components of the S&P 500 index, trading up 15.5%.

Year to date, Equifax registers a 15.4% gain.

In early trading on Thursday, shares of Equifax topped the list of the day's best performing components of the S&P 500 index, trading up 15.5%.

Year to date, Equifax registers a 15.4% gain.

And the worst performing S&P 500 component thus far on the day is Marketaxess Holdings, trading down 4.8%.

Marketaxess Holdings Inc is lower by about 12.7% looking at the year to date performance.

Two other components making moves today are Micron Technology, trading down 4.4%, and Pool, trading up 8.1% on the day.