The price at which a bond trades is influenced by the outlook for the business, average interest rates in the market, and a company's financial results. Bonds of companies perceived as risky tend to trade at discounts to the bonds' face value, while bonds from lower-risk companies trade at premiums to par.
Notably, bond prices are not much influenced by a company's stock price. While stocks represent company ownership, bonds are just loans to corporations. The face value of a bond at redemption plus the interest that it pays is essentially what a bond is worth.
Rising junk bond prices tend to indicate an improving economy. Declining junk bond prices are generally a sign of poor or worsening economic conditions.