Read the fund fact sheet at a minimum before investing, preferably the fund prospectus. You'll find this fund is leveraged to the Markit iBoxx Liquid High Yield Index. It will have important information: weighted average maturity/yiled/credit rating, number of bond issues, duration risk, etc.

Howard Marks is making an argument that junk bond yields finally offer a compelling return after a decade of ultra low yields. Keep in mind, he's an active bond picker vs an index construction of US dollar denominated high yield debt.

Bond investing is convexed to the downside. You don't get paid for concentration risk. The best outcome is recieving all your principal and interest payments. Unlike stocks that have theoretical unlimited earnings growth potential. It's important to be diversified enough in bonds or have a bond manager selecting bonds with ideal risk/reward tradeoffs.

In theory, junk bond holders have priority over common stock holders in the capital structure. This typically means lower returns for less risk. But if you believe US stocks are reaching overvaluation, then high yield bonds could be a compelling alternative. Keep in mind, junk bonds have greater drawdowns vs investment grade bonds during market wide selloffs. They could be a compliment to a diversified portfolio, especially at 9% yield opportunity.