The e-commerce giant ended trading at $1998.10 and contributed more than 28 positive points to the market index. That beats out Apple's 14-point positive impact and Microsoft's 12-point positive impact. The index has been trading at record levels all week amid overall market gains.
Amazon stock is up 70 percent in 2018 and has more than doubled in the last 12 months.
Separately Wednesday, Amazon rejected claims by Sen. Bernie Sanders of poor worker conditions in a rare political statement for the e-commerce giant.