Dollar-Cost Averaging vs Investing a Lump Sum
Automatic monthly investing is dollar-cost averaging done for the right reason. Sitting on a windfall is usually done for the wrong one.
At a glance
Figures checked 1 Sep 2026
What to take away
- Investing a lump sum immediately has historically beaten spreading it out, most of the time.
- Spreading it out reduces the worst-case regret, which has real behavioural value.
- Regular contributions from a salary are not a market-timing decision at all.
Two different things share the name. Investing part of each paycheque as it arrives is simply how earning and saving work. Deliberately holding a lump sum in cash and releasing it over twelve months is a timing decision.
What the evidence suggests
Because markets rise more often than they fall, investing everything at once has beaten spreading it out in roughly two-thirds of historical periods. Averaging in wins when the market falls shortly after you start.
If a lump sum is large enough that a 30% fall the week after investing would make you sell, averaging in over six to twelve months is a rational price to pay for staying invested.
Common questions
You are then holding cash indefinitely against an unknown date. The historical cost of waiting has typically exceeded the benefit of a better entry.