In the context of the input sentence, determine the relationship between 'Nomura Holdings' and 'Nomura Securities'.
Options: stock exchange, subsidiary, creator, publisher

He previously held senior roles at Nomura Securities Co, the brokerage unit of Nomura Holdings Inc. After he left Nomura, Saito served as CEO of the Industrial Revitalization Corporation of Japan, a now-defunct state-backed turnaround fund that invested in troubled companies.
subsidiary