Not too many average Joe's are invested in junk bonds, so the public really isn't walking into this. A bubble bursting in the junk bond market isn't going to produce anything like 2007.

If so, I'd say a significant portion of the public is being led into it.

Those are usually rated AA+ or better. I don't know of any large pension funds that allow buying junk bonds. That doesn't mean there are not any, but I would suspect it is rare.

I read that in 2007/8, the "junk bonds" were actually AAA rated . . . does that no longer happen?

Article I read, here: http://www.investopedia.com/ask/answers/041515/what-role-did-junk-bonds-play-financial-crisis-200708.asp

but it's been flat for weeks, barely above and below an 18,000 Dow.

Having finally realized the party is over (I figured that out in April), he's looking for another bubble for his billions.

Good luck, buddy, the only way to create bubbles is to have a strong middle class with cash or unlimited credit to invest in them. None of these conditions exist now. The present stock market bubble was created by the government through quantitative easing. That tap is no longer functional and unless the billionaires and the banksters can talk the government into printing more funny money for them, they're about to get hosed.