Here's how much interest a $150,000 18-month CD can earn now (and why it's worth opening)

Park $150,000 in an 18‑month CD at today’s top rates (~4.20%–4.35%) and you’d earn roughly $9,500–$9,900 when it matures.
CDs give a fixed, guaranteed return and protect that money from market volatility—good if you prefer certainty over chasing higher but uncertain stock gains.
18 months is a nice balance (access again in 2027); shop around (online banks often pay best) and be mindful of potentially steep early‑withdrawal fees.