help- econ question 9 vol1 ex1

—Both expected inflation and GDP is much higher than current.— The answer says cash investments will provide better returns coz interest rates will go up with inflation. stocks and bonds will return poor. This makes sense alright. But, if expected GDP and Inflation is high, doesnt it mean that economy will be expending?? so stocks should be higher? this econ stuff is driving me crazy, one thing affects another, its like chicken comes out of egg or egg comes out of chicken. Is there a way to look at these types of sitiations to get the questions right?