Risk.
In plain English
Risk is the possibility that an investment does not do what you hoped. Prices can fall, a company can cut its dividend, or inflation can quietly eat your return. In investing, risk and expected reward usually travel together: assets that can pay more, like stocks, also swing harder and can lose value for years, while safer assets, like a savings account, pay less but rarely fall. Risk is not something to erase, because avoiding it entirely means accepting very low returns. The goal is to take an amount of risk you can hold through a bad stretch without selling at the bottom.
01Why it matters
The amount of risk that fits you decides both how much your money can grow and whether you can stay invested when prices drop.
02The math, step by step
Over one year a broad stock fund might gain 25 percent or lose 20 percent, while a savings account pays a steady 4 percent. The stock fund has a higher expected return and much higher risk.
03What this is NOT
Risk is NOT just how much a price bounces around. Volatility is one kind of risk, but a permanent loss, like a company going bankrupt, matters more than day-to-day swings.