This study analyzes unlawful investment strategies of global investment banks, focusing on the case of Goldman Sachs' synthetic CDO product, as known as ABACUS. The legal battle between Goldman Sachs and the Securities and Exchange Commission (SEC)began when the SEC filed a complaint on April 16, 2010, and ended up with the settlement on July 15 through which both parties agreed upon that Goldman Sachs should pay a fine of $550million. During the sales of ABACUS, Goldman Sachs failed to inform its investors of material facts related to the meltdown of the US housing market, and thereby inflicted huge damages on these investors. What Goldman Sachs deliberately omitted from its ABACUS marketing materials was the role that Paulson & Co, one of the parties involved in the product, played in selecting underlying assets that constituted the product, which was expected to affect adversely the investors. Instead, Goldman Sachs included false information that the underlying assets were selected by ACA, a third party with expertise in selecting portfolio assets. Furthermore,although Paulson & Co took short position in the product, Goldman Sachs caused tremendous damages on investors by falsely informing ACA that Paulson & Co took long position just as other investors. As the result of the ruling, one of the main investors of the product, IKB could receive full compensation for their loss, while ABN AMRO, another investor, received only $100 million, much less than its actual losses. In response to the unreasonable compensation,other investors are expected to file a series of lawsuits. Already, ACA, one of the affected investors, filed a $120 million lawsuit against Goldman Sachs in January 2011. Since the outbreak of this event, the US regulations on global financing have been strengthened. The Wall Street Reform and Consumer Protection Act that came into effect in July 2010attempts not only to regulate proprietary trading as well as OTC derivatives trading of large financial institutions, but also to include detailed measures to protect financial customers. More importantly, the actions taken by the US will spread to other nations and become a new paradigm in the world's major financial markets. In addition, financial industries act quickly to self-regulate themselves. In January 2011, the Business Standards Committee established within Goldman Sachs last year released a report including how to revamp itself, in its attempt to reestablish its corporate brand as well as the confidence of the whole financial markets. Apart from how effective the attempts would be, this will definitely affect other financial institutions. This case study will help the Korean policy makers minimize the damages that any immoral investment strategies adopted by both Korean and global financial firms may inflict on Korean investors, and emphasize the morality and social responsibility of financial firms. Also, this may help Korean financial firms advance into a global player under the new global paradigm of toughened regulations.