50 000 000 000 Mark Gelsenkirchener Bergwerks-Aktien-Gesellschaft

Gelsenkirchener Bergwerks-AG — better known as GBAG — was one of the largest coal and steel conglomerates in the Ruhr, and like many industrial giants of 1923 it was authorized under emergency notgeld provisions to issue its own currency to pay workers when the Reichsbank simply could not supply enough physical notes to meet payroll. The hyperinflation peak that autumn rendered fifty billion marks a single day's wage.

GBAG's notes circulated almost entirely within company towns and company-controlled retail outlets, which is why survival rates vary so sharply by denomination — higher values were often redeemed quickly or discarded once the rentenmark stabilization made them worthless within weeks of issue.