roller coaster ride
A series or period of drastic changes that occur without warning. After she graduated from college, her life became a roller coaster ride filled with ups and downs as she tried to establish herself as a fashion designer.
a roller-coaster ride
If you describe an experience as a roller-coaster ride, you mean that parts of it were very good and parts of it were very bad. Markets on both sides of the Atlantic have had a roller coaster ride over the past five days. The past week was an emotional roller-coaster ride for these people.
a roller-coaster ride
an experience in which circumstances change rapidly and in a volatile manner from one extreme to another. 2004 BBC News: Business Shares have been on a rollercoaster ride, with US shares plunging and then recovering twice over.