In his latest note, David Rosenberg makes the case that the bull run can continue in part by comparing it to other bull runs.

As you can see below, gold's huge rally isn't anything compared to what other markets have seen. If you think there's a "bubble" now, you're not even in the right ballpark, he argues.

His call is for $3,000 and argues that if gold were to reach its old "price to world GDP peak" it could go to $5300.