The "Stop Predatory Investing Act" aims to amend the tax code to limit certain tax deductions for individuals or entities owning a significant number of single-family rental properties, specifically targeting large-scale property owners. The legislation seeks to prevent these owners from benefiting from interest and depreciation deductions, which are seen as encouraging predatory investing practices that can negatively impact the housing market. Key provisions of the act disallow interest and depreciation deductions for taxpayers who own 50 or more single-family rental properties.