The short answer
- New money coming in monthly → SIP.
- Windfall / bonus / inheritance → STP over 6–12 months, not lumpsum.
- Market clearly beaten down (drawdown > 25%) → lumpsum can outperform historically.
Why SIPs feel powerful
SIPs don't magically beat lumpsum — they beat *you*. They remove the two things that kill returns: timing and emotion.
When lumpsum wins
Backtested over 20 years in India, one-shot lumpsum beats SIP in ~60% of rolling periods — because markets rise more often than they fall. But the 40% where it loses, it loses badly.
The STP compromise
Park money in a liquid fund, transfer weekly/monthly into equity. You get most of the lumpsum upside with SIP-like discipline.
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