Lump sum means investing a large amount in one go. SIP (Systematic Investment Plan) means investing a fixed amount at regular intervals (e.g. monthly). Both are valid strategies for building your FIRE corpus.

Lump Sum vs SIP: The Data

Historically, lump sum has outperformed SIP more often—because markets tend to rise over time, and being invested earlier means more time in the market. SIP reduces the risk of investing everything at a market peak (timing risk) and smooths out volatility through rupee-cost averaging.

For FIRE Planning

• Lump sum — Use when you have a windfall (bonus, sale of asset, inheritance). Invest soon; don’t try to time the market.
• SIP — Use for monthly salary flows. Psychologically easier, fits most salaried FIRE aspirants, and removes the need to decide “when” to invest.

For most people, SIP in index funds is the default. If you get a lump sum, invest it in a disciplined tranche (e.g. 25% each quarter) or all at once—both beat sitting in cash for long.