Born in 1990 — the Year of 庚午 (Metal Horse)
Yang Metal (庚) sits above Yang Fire (午) — the Year of the White Horse.
Year pillar
The 1990 year pillar is 庚午. 庚 is Yang Metal — forged metal, an axe, a blade — while 午 is Yang Fire, the noonday sun.
Metal above Fire is classically read as 'refining' — the native comes into their value through processes of pressure and shaping.
Shared tendencies
A year pillar alone does not define a person, but 1990-born natives are often described as growing through external pressure and change. They carry decisiveness and momentum once direction is set.
Accurate reading requires looking at month, day, and hour pillars together.
One calculation caveat
The Saju year flips at 立春 (~Feb 4), not Jan 1. Anyone born between 1990-01-01 and ~1990-02-03 actually carries the 1989 year pillar (己巳).