As we've chronicled some of the recent ETF registrations and launches, we've noticed a pattern take shape: Not content to invest in proxies for a particular type of market exposure, providers are now structuring products that deliver unadulterated exposure to the risks themselves.

We've already covered the forthcoming 'ETSpreads', which are a type of ETF that will invest in credit default swaps. Credit default swaps are prized by some investors, in part, because they offer a way to isolate and wager on credit risk. By contrast, if you invested in a bond, you'd court a host of other risks, such as interest-rate risk, curve risk, prepayment risk, etc.

Similarly, the recently registered MacroShares Medical Inflation Up Shares and companion MacroShares Medical Inflation Down Shares are tied to the medical care component of the CPI. In other words, these products give investors pure exposure to the risk of healthcare goods/services inflation.

True, ETF providers have blanketed the market with a dizzying array of commodity ETFs, which provide exposure to the physical commodities, or derivatives thereof. And those commodities, in turn, underpin risks such as particular types of inflation. For instance, as corn and grain prices have skyrocketed, food cost inflation has flared.

The problem, as a practical matter, with taking an 'a la carte', building-block-by-building block approach to hedging out these risks (by, say, buying an ETN that's tied to grain prices or a gasoline ETF) is that it can be very hard to calibrate the actual risk. For instance, I could go long grain to hedge the risk that it'll literally cost me more to put food on the table. But if the Krafts, General Mills, and Kelloggs of the world can't pass that along--maybe because they're getting squeezed by Wal-Mart--then my hedge doesn't work. Also, there's the prosaic question of cause and effect--it can be extremely difficult to pinpoint the root causes of a particular risk. How, for instance, would an investor hedge out the risk that tuition costs will continue to gallop higher (yeah, prepaid tuition plans are an option, though a highly imperfect one at that)?

Identifying these liabilities and devising a plan to fund them isn't the stuff of esoterica. Ask the many pension plans that have adopted highly-customized asset/liability matching programs to reduce the uncertainty associated with funding. And it extends to Main Street as well. Think, for instance, of the ballooning class of investors who, after spending years amassing their nest eggs, are embarking on the spending phase of their lives. At that stage, asset/liability matching takes on very stark, personal terms, as those liabilities often include one's ability to afford drugs and medical care, eke out a greater-than-subsistence-level standard of living (food and shelter), and leave a margin of safety in the event of the unforeseen (elder care, etc.). But even for those of us who haven't reached retirement, the question of how we'll meet future obligations and maintain a post-retirement standard of living looms.

Fund companies have responded in a few ways to this challenge. For instance, so-called life-strategy funds--which typically include 'target retirement' products--have become one of the most popular and fastest growing segments of the investment management business (see also: T. Rowe Price). Some of the larger providers have also devised 'managed payout' strategies, which are akin to annuities.

Yet, in these cases, it's still quite challenging for the investor to gauge 'how we're doing'. This isn't the fault of the fund companies, per se, as it's impossible to retail products that are tailored to an impossibly varied set of individual facts/circumstances. But the fact that these products are really just proxies for certain types of risks represents an inherent flaw. For instance, unless I know that the managed payout fund I've invested in hedges out exposures to the particular types of risks I face, there's no telling whether those payouts will prove adequate.

That creates an opening for products like the MacroShares and ETSpreads. While these are hardly perfect investments--both are founded on complex, unproven structures (MacroShares' oil products have essentially bombed)--they might serve as a blueprint for other providers. The objective? Giving investors, and the advisors who serve them, a way to more precisely dial-in risks that they face, be it the cost of food, energy, shelter, or healthcare. Also, from an institutional manager's standpoint, just as CDS have soared in popularity in recent years, it seems likely that 'risk-focused' products that isolate exposures in a similar way would resonate.

For those reasons, I think we're going to see many more of these kinds of ETFs in the future.