Amazon became the fifth largest U.S.-listed company by market value on Monday.
The company surged past Berkshire Hathway to a market cap of about $356 billion. Berkshire's market value sat at about $355 billion.
The online retailer also hit an all-time intraday high of $755.90 on Monday. The stock was last up about 1 percent.
This is good news for Amazon ahead of its second annual Prime Day on Tuesday, which some analysts have projected could be the biggest day ever for the e-commerce giant.