This is a problem I ran across at my job. I have no statistics experience so that might explain if this problem is exceedingly simple:

My problem is to test whether there is a relationship between a selected bond index and a selected stock index. Specifically, the goal is to test whether a movement in the bond index predicts the same movement in the stock index six months later.

What I have done so far is calculated the % change in each index for each quarter available. I'm not sure where to go from here. I was thinking of doing a simple correlation test between the two variables with a 6 month time lag but after reading definitions of correlation this doesn´t seem right. Is there a better test I could run?