This book focuses on the Indonesian Financial Service Authority (FSA), which is a newly established authority within Indonesian financial services institutions that has emerged as the ultimate decision-maker for portfolio investment liberalization. In doing so, the book elaborates on how the emergence of the Indonesian FSA has resulted in implementation gaps in Indonesia, in the area of portfolio investment liberalization. The book reveals that the endowment of an ‘independent and free’ status, as well as the FSA’s power over the Indonesian financial sector, has allowed agents in the FSA to provide different positions or responses to the already agreed ASEAN financial liberalization initiatives. Contrary to the expectations of most writers that the independent status of an institution would advance financial liberalization, this book shows that the ‘independent and free’ status of the Indonesian FSA has actually stymied financial liberalization. To achieve this, thebook employs a modified account of the historical institutionalism approach, or ‘the agents-in-context’ approach, examining how and why the Indonesian FSA has emerged as an independent authority. The insights drawn from applying a modified historical institutionalism approach to the case study of Indonesian portfolio investment liberalization critiques and complements existing works in the regionalism literature in general, and ASEAN financial integration particularly.