A series or period of drastic changes that occur without warning. After she graduated from college, her life became a roller coaster filled with ups and downs as she tried to establish herself as a fashion designer.
a situation which changes suddenly and often between being good and being bad
Usage notes: A roller coaster is a type of small railway in an amusement park which travels very quickly climbing up and down hills.
The Norwegian stockmarket has been on a roller coaster during the past 18 months.What the book does describe very well is the emotional roller-coaster of puberty.