tax free investments

There's an old investing axiom that says "there's no such thing as a free lunch" - which basically tells us we can't earn a profit without taking some risk.

And whether or not the United States defaults on its debt when the federal government hits its debt ceiling on Tuesday, the threat by Standard & Poor's to downgrade the United States' top-tier AAA credit rating means there will also be no such thing as a "risk-free" investment.

This new financial reality will alter the global-investing landscape forever.

And though it will put a hurting on hedge funds, investment banks and the rest of Wall Street, the death of the risk-free investment may prove beneficial to those of us who are America's ordinary retail investors.

Let me explain ...

Modern Portfolio Tomfoolery

A central assumption of modern financial theory (also known as "modern portfolio theory," or MPT) is about to collapse: From Aug. 2 forward, there will no longer be such a thing as a "risk-free" investment. Banks and hedge funds will be turned upside down, but even those of us who regard modern portfolio theory as mostly rubbish will discover that the financial markets have started to function in very different ways.

Modern financial theory was originally developed at Carnegie-Mellon and the University of Chicago in the 1950s, and since then has become a dominant element of every Wall Street operation (helping Wall Streeters make boatloads of money, as a result).

One of the core precepts is that there are such things as "risk-free" investments, in which an investor's principal is 100% safe - not 99.5% safe, but 100%.

For example the Capital Asset Pricing Mode (CAPM), a central theorem of modern financial theory, says there is a "frontier" of optimal investments, and that investors can achieve any mix of risk and return on that frontier by combining risky and risk-free investments (or, to increase risk, leveraging themselves).

Similarly, the Sharpe Ratio, used by professional investors in hedge funds and pension funds, evaluates securities and portfolios by the "excess return" generated over a risk-free investment. That helps money managers determine whether they are paid sufficiently for their risk. In options theory, the Black-Scholes model assumes the ability to "delta hedge" an option by buying or selling the underlying security, and borrowing or investing the proceeds at the same risk-free rate.

Finally, risk-management theory assumes the possibility of eliminating risk from portions of the portfolio, so that the Basel bank regulatory systems, for example, weight Treasury securities of Organisation for Economic Co-operation and Development (OECD) governments at zero. That allows banks to hold unlimited quantities of Treasuries, without having to allocate capital to those holdings.

The Death of the "Risk-Free" Investment

If U.S. Treasuries are not AAA-rated, then they are not risk-free - pure and simple.