Glossary
Dollar-cost averaging
Investing a fixed amount at fixed intervals regardless of price.
Put in $500 on the first of every month and you buy more shares when prices are low and fewer when they are high, without needing to predict anything.
It usually underperforms investing a lump sum immediately, because markets rise more often than they fall. Its real value is behavioural: it removes the decision, and the decision is where most people destroy their returns.