The stock market rally of 2023 has surprised even Wall Street veterans. Here are the 10 best-performers on the S&P 500 and what could be driving them.

• The rally is US stocks this year has surprised even Wall Street veterans, following a dismal 2022.
• The S&P 500 rallied nearly 9% this year, driven mainly by expectations of cooling inflation. 
• Tesla, Catalent and Nvidia are the top three preforming stocks on the benchmark US stock index.  

After US stocks' dismal performance in 2022, many Wall Street experts expected more pain in the market this year. But they've performed so well in the early going that even longtime investors have been taken aback.