Example from Seth Klarman:
Financial distress created such an opportunity in the debt and equity securities of the Bank of New England Corporation (BNE). A large loss announced in January 1990 caused the subordinated bonds of BNE to plunge to 10 to 13 from levels in the 70s. At the same time the common stock of the Bank of New England traded at approximately $3.50 per share.
Overall BNE had roughly $700 million face amount of senior and subordinated debentures outstanding with a total market value of less than $100 million. The common stock, which was, of course, junior to the holding company bonds, had a total market capitalization of approximately $250 million.
Opportunistic investors bought the BNE bonds and sold BNE common stock short to lock in an apparent valuation disparity. Specifically, investors could purchase the bonds at 10 to 13 and sell short common stock in equal dollar amounts. A buyer of $1 million face amount of subordinated bonds at 10 ½ (for $105,000) could sell short 30,000 shares of common stock at $3.50 for equivalent net proceeds. Performing these simultaneous transactions appeared to be a low-risk strategy under any conceivable scenario.
If BNE became insolvent (as happened in early 1991), for example, bondholders would at worst lose their investment and might possibly achieve some recovery; the common stock would certainly be rendered worthless. The loss on the bonds would at least be offset by the gain on the short sale of common stock. In addition, investors would earn interest on the short sale proceeds and might receive one or more interest payments from BNE (two semiannual coupons, as it turned out).
If BNE survived, the bonds seemed likely to rally by a greater percentage than the common stock. If the common stock triples to $10.50 amidst a surprising recovery for example, the bonds seemed likely to trade well above the 30 to 40 level that bondholders would need to breakeven. Again, investors would also benefit from interest payments received on the bonds as well as interest earned on the short credit balance.
Another possible scenario was a financial restructuring, whereby BNE would offer bondholders the opportunity to convert into equity. This alternative, which was seriously considered by the bank but ultimately proved to be unworkable, would have been highly favorable for those who were long bonds and short stock. The bonds would have benefited from the premium above market that the company would have had to offer to induce holders to exchange, while the common stock would likely have declined due to the dilution and selling pressure resulting from the issuance of large amounts of common stock to bondholders.