“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).