Zurich Cantonal Bank (German: Zürcher Kantonalbank, or ZKB) is the largest cantonal bank and fourth largest bank in Switzerland, as well as the leading financial services provider in the Greater Zurich area, with total assets of over CHF 150 billion.The Zurich Cantonal Bank was founded in 1870 as "bank of the citizens of Zurich" following an initiative of Johann Jakob Keller (1823–1903), then member of the cantonal council of Zurich.