Types of Compound Interest
There are four main categories of compound interest, organized by the frequency and timing of interest compounding: Daily Compounding, Monthly Compounding, Quarterly Compounding, and Annual Compounding.
Main Categories
- Daily Compounding — interest is compounded daily, resulting in higher returns due to more frequent compounding, as seen in Ally Bank's online savings account, which compounds interest daily.
- Monthly Compounding — interest is compounded monthly, providing a balance between frequent compounding and lower administrative costs, as used by Bank of America's checking accounts, which compound interest monthly.
- Quarterly Compounding — interest is compounded quarterly, often used for investments with lower liquidity, such as certificates of deposit (CDs), as offered by Wells Fargo, which compounds interest quarterly on its CDs.
- Annual Compounding — interest is compounded annually, typically used for long-term investments with low liquidity, such as bonds, as seen in the US Treasury's 10-year bond, which compounds interest annually.
Comparison Table
| Category | Compounding Frequency | Administrative Cost | Return on Investment |
|---|---|---|---|
| Daily Compounding | Daily | High | High, e.g., Ally Bank's 2.20% APY (Ally Bank) |
| Monthly Compounding | Monthly | Medium | Medium, e.g., Bank of America's 1.50% APY (Bank of America) |
| Quarterly Compounding | Quarterly | Low | Low, e.g., Wells Fargo's 2.00% APY (Wells Fargo) |
| Annual Compounding | Annually | Very Low | Very Low, e.g., US Treasury's 2.50% yield (US Treasury) |
How They Relate
The categories of compound interest overlap in terms of their application to different financial products, such as savings accounts, CDs, and bonds. Daily Compounding and Monthly Compounding are often used for liquid investments, such as savings accounts and money market funds, while Quarterly Compounding and Annual Compounding are used for less liquid investments, such as CDs and bonds. Specifically, Daily Compounding and Monthly Compounding are commonly confused, as both provide relatively frequent compounding, but Daily Compounding results in higher returns due to more frequent compounding. In contrast, Quarterly Compounding and Annual Compounding are distinct, as Quarterly Compounding provides more frequent compounding than Annual Compounding, resulting in higher returns. Ricardo's comparative advantage model (1817) can be applied to understand the trade-offs between these categories, as investors seek to maximize returns while minimizing administrative costs.