Investment income is money municipalities earn from investing their reserve funds and operating cash balances. Rather than letting money sit idle, municipal treasurers invest funds in permitted securities like government bonds, guaranteed investment certificates, and money market instruments. Provincial legislation restricts municipal investments to low-risk options that protect public funds. Investment income supplements other revenues, helping fund operations or build reserves. The amount earned depends on interest rates, the size of invested balances, and investment strategy. Larger municipalities with substantial reserves can generate significant investment income, reducing reliance on property taxes.