A U.S. one dollar banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A Turkish lira banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A Turkish lira banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A U.S. one dollar banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A British Pound banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A Chinese Yuan banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A Chinese Yuan banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

A British Pound banknote is seen in front of displayed stock graph in this illustration taken May 7, 2021. REUTERS/Dado Ruvic/Illustration

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, May 7, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, May 6, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, May 5, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, May 4, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, May 3, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 30, 2021. REUTERS/Staff

Dutch engineer and inventor Peter van Wees points at the result graph of a COVID-19 test in front of his invention, the quick breath analyzer QuBA that scans exhalation air for the coronavirus instead of taking unpleasant nasal swab tests, amid COVID-19 pandemic, in Remscheid, Germany April 30, 2021. REUTERS/Wolfgang Rattay

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 29, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 28, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 27, 2021. REUTERS/Staff

German Economy Minister Peter Altmaier holds a graph during a press conference to present the government's economic spring projection in Berlin, Germany, April 27, 2021. John Macdougall/Pool via REUTERS

German Economy Minister Peter Altmaier shows a graph during a press conference to present the government's economic spring projection in Berlin, Germany, April 27, 2021. John Macdougall/Pool via REUTERS

German Economy Minister Peter Altmaier holds a graph during a press conference to present the government's economic spring projection in Berlin, Germany, April 27, 2021. John Macdougall/Pool via REUTERS

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 26, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 23, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 22, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 21, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 20, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 19, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 19, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 16, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 15, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 14, 2021. REUTERS/Staff

A man walks in front of the board showing the graph of the German share price index DAX at the stock exchange in Frankfurt, Germany, April 13, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 12, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 9, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 8, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 7, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, April 1, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 31, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 30, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 29, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 26, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 25, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 24, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 23, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 22, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 19, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 18, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 18, 2021. REUTERS/Staff

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 17, 2021. REUTERS/Staff

Words reading "COVID-19 Infected people", the Bosnian flag, and a stock graph are seen displayed in this illustration picture taken March 17, 2021. REUTERS/Dado Ruvic/Illustration

Austria's Chancellor Sebastian Kurz holds a graph as he attends a news conference in Vienna, Austria March 16, 2021. REUTERS/Leonhard Foeger

Vials labelled with broken sticker "AstraZeneca COVID-19 Coronavirus Vaccine" are seen in front of a displayed stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

A representation of virtual currency Bitcoin is seen in front of a stock graph in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

The German share price index DAX graph is pictured at the stock exchange in Frankfurt, Germany, March 15, 2021. REUTERS/Staff