Copied 9729 4th Ave Unit C3, Brooklyn, NY 11209, US $555,000 9729 4th Ave Unit C3, Brooklyn, NY 11209 Checked: 21 hours ago Updated: Jul 11, 2025 at 11:26PM Investment Summary Net Operating Income (NOI) minus mortgage payments. Calculation: NOI - Mortgage Payments Monthly Cash Flow -$1,977 Capitalization Rate is a rate of return that compares the yearly Net Operating Income (NOI) to the market value.