Sharia-compliant investing is built around the principle that money should not generate money simply by the passage of time. As a result, riba, commonly understood as interest or usury, is prohibited. This means conventional interest-bearing lending and borrowing structures are not acceptable within Sharia, and investment arrangements must avoid receiving or paying interest. Instead, Sharia-compliant products aim to generate returns through permissible trading and investment activity, typically by linking profit to the performance of an underlying asset or business activity and by structuring returns as profit-sharing, mark-up on trade, rental income, or participation in tangible assets rather than interest on debt. The prohibition is not about timing, so it is not the case that interest becomes acceptable if credited at the end of a contract or paid upfront. Likewise, it is not restricted to whether a bank is authorised; the issue is the nature of the return itself. In exam terms, the key takeaway is that interest is fundamentally impermissible, which drives the design of Islamic financial instruments and the screening of investments for Sharia compliance.