Compound Interest
The quiet force behind long-term wealth
What compounding means
Compound interest is earning returns not just on your original money, but also on the returns it has already generated. Over short periods the effect is small — over decades, it becomes the single biggest driver of investment growth.
A simple example
$10,000 invested at 8% annual return becomes about $21,600 after 10 years, but about $46,600 after 20 years — more than double, not just double the time. The growth accelerates the longer the money stays invested, because each year's gains start earning their own gains.
Why starting early matters more than the amount
Someone who invests $200/month starting at 25 will, in most scenarios, end up with more money by retirement than someone who invests $400/month starting at 35 — simply because their money had more years to compound. Time in the market is the one input in this equation you can never get back.
The same math works against you in debt
Compounding is neutral — it also applies to high-interest debt like credit cards. A balance left unpaid compounds against you the same way an investment compounds for you, which is why paying off high-interest debt is often the best guaranteed "return" available.