"It's like investing in gold in 1997," says bond man Jeff Gundlach of his favorite investing idea - natural gas - which DoubleLine is accumulating in one of its funds. On the question of QE3, he says we're already doing it - it's called Operation Twist - and when it's over he expects equities to struggle. Stock valuation in general right now? The PE on major indices should be in the single digits. Q&A here. Blog here.