If cash is already available and your horizon is long, investing sooner usually has higher expected wealth because markets trend upward over long periods. If anxiety would cause you to stall for months, a scheduled DCA can be the rational second-best plan.
Decision tree that works in practice
- Long horizon + high risk tolerance: favor lump sum into your target allocation.
- High anxiety or uncertain job cash flows: DCA over 3–12 months.
- Near-term spending needs: do not force equity deployment either way.
Trade-offs at a glance
| Approach | Strength | Weakness |
|---|---|---|
| Lump sum | More time in market | Higher short-term regret risk |
| DCA / SIP | Smoother entry psychologically | Can lag if markets rise steadily |
| Cash → scheduled transfers | Keeps cash productive modestly | Needs a written end date |
Conclusion
Choose the strategy you will complete. Perfect expected-value math loses to unfinished plans. Write the rule, automate it, and move on.