“If you look at the probability that you’ll end up with a higher cumulative value, the study shows it’s overwhelmingly when you use a lump-sum investment [approach] versus dollar-cost averaging,” said Matt Stucky, senior portfolio manager of equities at Northwestern Mutual Wealth Management.
The study looked at rolling 10-year returns on $1 million starting in 1950, comparing results between an immediate lump-sum investment and dollar-cost averaging (which, in the study, assumes that $1 million is invested evenly over 12 months and then held for the remaining nine years).
Assuming a 100% stock portfolio, the return on lump-sum investing outperformed dollar-cost averaging 75% of the time, the study shows. For a portfolio composed of 60% stocks and 40% bonds, the outperformance rate was 80%. And a 100% fixed income portfolio outperformed dollar-cost averaging 90% of the time.