Amazon stock fell 5 percent during Monday trading after President Donald Trump resumed his attacks on the tech giant with a morning tweet criticizing the firm for exploiting the U.S. Postal Service and devastating brick-and-mortar retailers.

The loss, which wiped out more than $36 billion in Amazon’s market value, came as the Dow plunged 758 points on the day amid intensifying trade-war fears.

[jwplayer ZWTBkVij-wKJ9CRQU]

Trump’s Monday morning tweet bemoaned the perceived imbalance of Amazon’s relationship with the U.S. Postal Service and the firm’s detrimental effect on the nation’s traditional retailers. The USPS charges Amazon a uniform rate applied to all bulk shippers and the company currently collects sales tax in all states that require it.

The tweet — Trump’s fourth discussing Amazon in the last week — comes after a Wednesday Axios report indicated Trump brings up his hostility toward the company whenever the conversation turns to regulating Facebook.

Trump has reportedly remained focused on attacking Amazon — in part due to his dislike for Amazon founder Jeff Bezos and the Bezos-owned Washington Post — despite the recent spate of negative coverage of Facebook’s failure to protect user data.