Porsche chief executive Oliver Blume, right, and chief financial officer Lutz Menschke ring the opening bell during the IPO of German car maker Porsche at the Frankfurt Stock Exchange on Thursday. EPA
Porsche chief executive Oliver Blume, right, and chief financial officer Lutz Menschke ring the opening bell during the IPO of German car maker Porsche at the Frankfurt Stock Exchange on Thursday. EPA

Porsche debuts with $72bn price tag in Germany's biggest IPO in 25 years