There are no guarantees in the market. If there was I'd be a billionaire right now.
You can place it in an lazy/bogleheads portfolio if you want to reduce risk and even that is not guaranteed.
The only difference between what I said and an ETF is $TSLA will turn $100,000 into $1M in a decade but the ETF will only turn $100,000 into $400,000 in that same time frame (if the SPY continues its 10-year returns.)