Does dollar-cost averaging beat investing everything at once, according to the research?

Dollar-cost averaging means investing fixed amounts on a regular schedule regardless of price. Research from Vanguard has found that investing a lump sum immediately beats spreading it out about two-thirds of the time, simply because markets rise more often than they fall, so money invested sooner has more time to grow. That said, dollar-cost averaging shines in two ways: it's how most people naturally invest from each paycheck, and it reduces the regret and anxiety of putting a big sum in right before a drop. If you have a windfall and the math favors lump-sum but the emotional risk of a bad-timing crash would rattle you, splitting it over a few months is a reasonable compromise. The worst choice is letting cash sit uninvested out of fear.