As an economy develops, the wealth of the community increases, and an increasing proportion of it is held in the form of financial claims. Banking systems develop and, usually later, capital markets where companies and governments can tap savings directly. In the old western industrial economies, this process typically took quite a long time.
In Asia, these developments have been accelerated, as part of the rapid industrialisation and development of these economies in the past generation. By now, in some cases the sizes of financial systems are getting pretty large.