The main role of banks, well into the 1920, was to allocate capital to businesses (directly and through consumer credits and mortgages). Deposit-taking was a core function and the main source of funding. As far as depositors were concerned, banks guaranteed the safety and liquidity of the store of value (cash and cash-equivalents).
In the 1920, stock exchanges began to compete with banks by making available to firms other means of raising capital (IPOs - initial public offerings). This activity gradually became as important as the stock exchange's traditional competence: price discovery (effected through the structured interactions of willing buyers and sellers).
This territorial conflict led to an inevitable race to the bottom in terms of the quality of debtors and, ultimately, to the crash of 1929 and the Great Depression that ensued. Banks then were reduced to retail activities, having lost their investment services to hybrids known as "investment banks".
The invention of junk bonds in the 1980s heralded a whole new era. A parallel, unregulated financial system has emerged which catered to the needs of businesses to raise risk capital and to the needs of those who provided such funds to rid themselves of the hazards inherent in their investments. Consumer credits and mortgages, for instance, were financed by traditional banking businesses. The risks associated with such lending were securitized and sold to third parties.
As expertise evolved and experience accumulated, financial operators learned to slice the hazards, evaluate them using value-at-risk mathematical models, tailor them to the needs of specific customer profiles, hedge them with complex derivatives, and trade them in unofficial, unregulated, though highly liquid amorphous, virtual "marketplaces".
Thus, stock exchanges have begun to lose their capital allocation functions to private equity funds, hedge funds, investment banks, and pension funds. In the process, such activities have become even more opaque and less regulated than before. This lack of transparency led to pervasive counterparty distrust and difficulties in price discovery. Ultimately, when the prices of underlying assets (such as housing) began to tumble, all liquidity drained and markets seized and froze.
Thus, at the end of 2006, the global financial system was comprised of three main groups of actors: traditional retail banks whose main role was deposit taking and doling out consumer credits; exchanges whose main functions were price discovery and the provision of liquidity; and investment banks and their surrogates and special purpose vehicles whose principal job was the allocation of capital to businesses and the mitigation of risk via securitization and insurance (hedging).
Yet, these unregulated investment banks were also often under-capitalized and hyper-leveraged partnerships (at least until the late 1990s, when some of them went public). This is precisely why they had invented all manner of complex financial instruments intended to remove credit-related risks from their books by selling it to third parties. Physicists, analysts, and rating agencies all agreed that the risk attendant to these derivatives can be calculated and determined and that many of them were risk-free (as long as markets were liquid, of course).
The business strategy of the investment banks was viable. It should have worked perfectly had they not committed a primal sin: they have entered the fray not only as brokers, dealers, and mediators, but also as investors and gamblers (principals), taking on huge positions, often improperly hedged ("naked"). When these bets soured, the capital base of these institutions was wiped out, sometimes literally overnight. The very financial instruments that were meant to alleviate and reallocate risk (such as collateralized debt obligations - CDOs) have turned into hazardous substances, as investors (and investment banks) gambled on the direction of the economy, specific sectors, or firms.
In hindsight, the "shadow banks" subverted the very foundations of modern finance: they created money (modifying the money-printing monopoly of central banks); they obfuscated the process of price discovery and thus undermined the price signal (incidentally casting doubt on symmetrical asset pricing models); they interfered with the ability of cash and cash-equivalents to serve as value stores and thus shook the trust in the entire financial system; they amplified the negative consequences of unbridled speculation (that is not related to real-life economic activities and values); they leveraged the instant dissemination of information to render markets inefficient and unstable (a fact which requires a major revision of efficient market hypotheses).
This systemic dysfunctioning of financial markets led risk-averse investors to flee into safer havens: commodities, oil, metals, real estate and, finally, currencies and bonds. This was not merely a flight to quality: it was an attempt to avoid the abstract and fantastic "Alice in Wonderland" markets fostered by investment banks and to reconnect with tangible reality
With the disappearance of investment banks (those who survived became bank holding companies), traditional banks are likely to regain some of their erstwhile functions: the allocation to businesses and creditworthy consumers and homeowners of deposit-based capital. The various exchanges will also survive, but will largely be confined to price discovery and the allocation of risk capital. Some financial instruments will flourish (credit-default swaps of all types), others will vanish (CDOs).
All in all, the financial scenery of 2010 will resemble 1910's more than it will 2005's. Back to basics and home-grown truths. At least until the next cataclysm.