BNP Paribas sold €163M in securities for €326K — a fat finger that cost €160M

BNP Paribas Arbitrage was the structured products trading arm of BNP Paribas, one of Europe's largest banks. It handled complex equity and index-linked products.

On December 2, 2015, a BNP Paribas trader sold 3,000 units of a structured security to German trader Armin S. at the posted price of €108.80 per unit — a total of €326,400. The correct price should have been €54,312 per unit, valuing the trade at approximately €163 million. BNP even reconfirmed the sale at the wrong price.

The error went unnoticed for days. The Financial Times later reported that BNP had failed to book any of its structured products trades in Germany from December 2 to December 9, 2015 — meaning it had no record of its own trades. BNP did not try to cancel the trade until the seventh trading day, far past the regulatory deadline of the next business day.

Armin S. filed a €1 million civil suit in Frankfurt in 2017, then a €152 million suit in France. BNP won dismissal in 2019 when the German court ruled that Germany was not the relevant jurisdiction. The case highlighted that BNP's systems failed to detect a €163M error for a week, and the ECB and BaFin were notified.