Investments are like...
A Rollercoasters
Investments are like roller coasters because...
On a roller coaster, sometimes you are up and sometime you are down. Just like a investment you aren't always going up and your not usually always going down. Like a roller coaster when you start a investment you often go up because, why would you join that investment in the first place if it wasn't already going up. Sometimes on investments are you going straight up but for the most part there will always be that peak and you will go down.