When Yoni Jacobs' book "Gold Bubble: Profiting from Gold's Impending Collapse" was published in April 2012, gold was trading around $1,650 per ounce. Now gold is below $1,300. But Jacobs, the chief investment strategist at Chart Prophet Capital, doesn't think the gold plunge is over just yet.

"The long-term target is still $700, which sounded a lot more ridiculous a few years ago" Jacobs said on Tuesday's "Futures Now."