Albuquerque investment advisor Lee Munson goes a step further, saying "What it is, it's a marketing gimmick."

Munson runs Portfolio Wealth Advisors, a private firm that manages some $200 million in assets. Prior to moving to Albuquerque, Munson penned the book "Rigged Money: Beating Wall Street at Its Own Game" and worked for a brokerage house on Wall Street.

"The problem and the devil in the detail is that step bonds usually come with call features," Munson notes, "which means that after a set period of time, that issuer - the place that sold you the bond - can pull it back before that interest rate goes up."

Bernalillo County County Commissioner Maggie Hart Stebbins says buying bonds with call features has handcuffed county finances.

"The county treasurer doesn't have the decision-making authority about when those bonds are called," Stebbins says, "The issuer has that power. And the issuer is going to make that decision based on what's good for his or her agency -- not us."

Of the 47 bond purchases reviewed by KRQE News 13, all but one had a call feature.

The gamble by Ortiz and Padilla meant that as long as the issuer called the bond in time to free up needed cash for the county, the pair could buy bonds with maturities well past the recommended date. Over the course of the last few years, the bets paid off in millions of extra money for Bernalillo County.

Now, with the prospect of higher interest rates inching ever closer, fewer bonds are getting called. Issuers prefer to leave their bonds -- which amount to a loan -- outstanding, knowing they can't borrow at a lower rate.

The math of the bond markets means the county can lose another way, too.

"When a bond is getting called," Munson says, "it means you lost the bet."

He explains that as interest rates fall, bond holders find it's cheaper to call their bonds in than issue new ones at a lower rate. As that happens, bonds that pay the old, higher rates gain value. Investors who hold bonds can then sell at a premium, getting back not just the face value of the bond they'd get at call, but a few extra bucks from buyers who are anxious to own a bond that pays a higher interest rate.

"It's a classic 'Heads, I win. Tails, you lose'," says Munson. Issuers of step bonds hold out the promise of higher interest rates than traditional bonds, all the while knowing that if the markets turn against them, they'll call their bonds in and start over.

The money the treasurer is charged with investing is earmarked for spending on maintaining roughly 100 county buildings as well as hundreds of miles of roads, scores of emergency vehicles and dozens of parks. After the Treasurer's Office was forced to sell bonds at a loss of $758,000 earlier this year, county leaders put many of those projects on hold. County leaders also ordered division heads to identify ways to trim 1 percent to 2 percent from their budgets.

The exit strategy advanced by Ortiz and Padilla hasn't been widely discussed at the top levels of county government. In fact, Stebbins told KRQE News 13, "I personally haven't gotten any information from the treasurer or the treasurer's office about what steps he intends to take next."

Stebbins says the lack of communication is worrisome, but adds that it's a product of a system in which voters elect a treasurer who has broad power to invest and, through an investment policy currently undergoing an emergency revision, is only partially accountable to the county commissioners when they meet as the Board of Finance.

"It is just the reality of the relationship between the county treasurer's office and the Bernalillo County Commission," Stebbins says.

Ortiz and Padilla have been heavily invested in bonds that mature at least a decade in the future. In many cases, the duo has bought bonds that won't mature until after the year 2030.

While bonds -- especially the government issues bought by Bernalillo County -- are generally considered safe investments, they're not without risk. Most governments buy bonds that have shorter maturities. If market conditions make them less valuable to other investors, governments can hold on to the bonds until their maturity date, then cash them in to pay for public services.

But buying longer-term bonds means the county has to sell them to access the taxpayer money that was used to purchase them. And -- as the county has seen -- selling a bond before it's due doesn't always mean making a profit.

The treasurer has already lost one bet to the tune of three quarters of a million dollars. If the county needed cash today, managers say losses would likely exceed $15 million and could very easily top $20 million.