Lumpsum Investing — When One-Shot Capital Deployment Beats Drip-Feeding
A lumpsum investment commits a one-time capital amount to a single asset or fund. While SIPs reduce timing risk via averaging, mathematically a lumpsum invested at the start of a long horizon outperforms an equivalent drip-fed contribution in roughly two-thirds of historical periods — simply because more money is exposed to compounding earlier. This calculator models pure exponential growth: FV = P × (1 + r)ⁿ.
The Formula
Compound interest at annual frequency: FV = P × (1 + r)ⁿ. The growth is fully determined by the rate–time product; doubling time approximates 72/r (the Rule of 72).
When to Use Lumpsum
- Bonus, inheritance, or sale-of-asset proceeds with a clear long horizon.
- Markets in deep drawdowns (−25% or more from peak) where mean-reversion odds favour deployment.
- Tax-loss harvesting recycle into a similar exposure.
Risks
If deployed at a cyclical top, a lumpsum can underwater for 3–7 years. Hybrid approach: deploy 50% lumpsum + 50% over 6–12 month STP into equity to balance time-in-market against timing risk.