What's the benefit of dollar-cost averaging vs lump sum investing?

The psychological comfort of DCA is real, but the math usually favors lump sum if you've got the cash available - historically, markets trend up more often than down, so sitting on money waiting to deploy it tends to cost you more than it saves. Where DCA actually wins is if you're genuinely adding new income over time (like monthly paychecks), since you're not choosing to hold cash; you're investing as money becomes available, which is a different scenario entirely.

Don't overthink this by waiting for the "perfect" entry point - nobody can time the market reliably, and delaying a lump sum investment because you're nervous about a potential crash often costs more than it saves.

The real tension here is that both approaches work, just differently depending on your situation. If you have a big chunk of money sitting around right now, dumping it in tends to win on average because markets spend most of their time going up. But here's what gets glossed over: if you genuinely can't afford to invest the whole amount at once, that's not even a choice - DCA is just how you do it. Same if the money is trickling in (bonus, inheritance installments, whatever). Those aren't decisions, they're just reality.

Where DCA actually matters is when you're anxious. If seeing your balance drop 20% in a downturn makes you panic-sell, then spreading purchases over months or a year can help you stick to the plan instead of bailing at the worst time. That behavioral edge might outweigh the math. But be honest with yourself about whether you'd actually panic - most folks assume they would but don't when it happens.