In astrology, the Anti-Vertex is the calculated point located exactly opposite the Vertex in the natal chart. Together, the Vertex and Anti-Vertex form an axis created through the relationship between the ecliptic and the prime vertical. Like the Vertex, the Anti-Vertex is not a physical celestial body but a mathematical reference point. Some astrologers consider the axis when exploring relational, interpersonal, or situational themes within the broader structure of a natal chart. Its meaning is interpretive and depends on the astrological method being used.