Despite its significance, the question of why the book of Zechariah was expanded with chs. 9-14 has largely been overlooked. By combining literary and sociohistorical insights, this article demonstrates that Zech 9-14 was composed as the continuation of Zechariah in order to bring the prophetic corpus up to date in light of the sociopolitical changes of the Ptolemaic period. As such, Zech 9-14 serves to enhance the authority of the prophetic revelation and to criticize these changes by means of a utopian/dystopian perspective.