Here are the top 15 performing stocks in the S&P 500

Ticker: FLT

Market cap: $23.3 billion

Year-to-date return: +44.4%

Description: Provides fuel cards and workforce-payment products and services

Ticker: XRAY

Market cap: $12.8 billion

Year-to-date return: +45.7%

Description: Dental-equipment maker and dental-consumables producer

Ticker: AMD

Market cap: $29.2 billion

Year-to-date return: +46.4%

Description: Semiconductor company and microchip manufacturer

Ticker: CELG

Market cap: $67 billion

Year-to-date return: +48%

Description: Biotechnology company

Ticker: SYF

Market cap: $24.2 billion

Year-to-date return: +48.9%

Description: Consumer financial-services company

Ticker: MSCI

Market cap: $18.9 billion

Year-to-date return: +50.9%

Description: Provider of market indexes and multi-asset portfolio-analysis tools

Ticker: ALGN

Market cap: $25.8 billion

Year-to-date return: +51.6%

Description: Orthodontics company, maker of invisalign teeth aligners

Ticker: CDNS

Market cap: $18.4 billion

Year-to-date return: +53.4%

Description: Electronic design-automation software and engineering services

Ticker: TSN

Market cap: $24.3 billion

Year-to-date return: +54.9%

Description: World's second-largest processor and marketer of chicken, beef, and pork

Ticker: XRX

Market cap: $7.2 billion

Year-to-date return: +62.0%

Description: Sells print- and digital-document and services

Ticker: HES

Market cap: $19.8 billion

Year-to-date return: +62.1%

Description: Energy exploration and production

Ticker: APC

Market cap: $36.5 billion

Year-to-date return: +65.7%

Description: Hydrocarbon exploration

Ticker: CMG

Market cap: $20.1 billion

Year-to-date return: +67.5%

Description: Fast-casual burrito chain

Ticker: COTY

Market cap: $10.2 billion

Year-to-date return: +104.7%

Description: Manufactures, markets, and distributes fragrances, cosmetics and hair-care products