Investors on the hunt for buying opportunities in equities probably haven't come across some of this year's notable success stories. That's because they are hiding in an illiquid, old-school market — and being traded by fixed-income desks.Why it matters: After Chapter 11, many companies are left for dead by the broader investing community — keeping their comebacks under the radar due to the private market in which they trade. SPACs (special purpose acquisition vehicles) are increasingly starting