[JoshTriplett]

Seconding the recommendation for Vanguard funds. And yes, five years is not long enough to amortize away a crash or substantial downturn, so if by "large risk" you mean "I don't mind not getting my original investment back" you might be fine, but if by "large risk" you just mean "I'm not going to panic at a little volatility" then you probably want something safer on a five-year timeline.

[lexapro]

A lot of people get this one wrong, risk is not volatility, risk is losing a portion (or in some cases all) of your money.

[JoshTriplett]

Over a sufficiently long term timeline for certain types of investments, the latter often turns into the former. Total-market stock funds on a 30-year timeline are volatile, but are unlikely to lose your money in any scenario in which money continues to have value. Total-market stock funds on a 5-year timeline have a substantial risk of getting out less than you put in, just from an ordinary downturn, let alone a major crash.

(I agree that the term "risk" often conflates a variety of things, and in this context should primarily mean "risk of losing your investment" rather than "day-to-day volatility".)

[carnitine]

Risk is uncertainty, it’s not about loss or gain. If I lever my portfolio 2x, I’m taking on twice the risk but if I’m in the money I’ll make twice as much.