Maybe not a knockout blow to London, but certainly a stiff jab.
The CEO and chairman of Goldman Sachs, Lloyd Blankfein, took to Twitter Thursday to offer fulsome praise of the German city of Frankfurt as a great place to do business.
In the tweet, Blankfein said: "Just left Frankfurt. Great meetings, great weather, really enjoyed it. Good, because I'll be spending a lot more time there."
Just in case anyone missed the point, Blankfein ended the tweet with "#Brexit".
Germany's Frankfurt and Paris, France, have both pushed themselves hard as a replacement location for London-based firms in the financial industry worried about the effect of Britain leaving the European Union.
In June, Goldman Sachs said it would "very probably" at least double its headcount in Frankfurt, where it currently employs 200 people.