There’s a kind of investment available in the market called a renewable, unsecured subordinated note. When the pros talk about them it sounds like “Russians,” from the RUSN acronym.

For most investors there’s just one thing about Russians really worth remembering, and that’s to stay away from them. The owners of many RUSNs issued by a suburban Twin Cities company called Aspirity Holdings probably have learned that the hard way.

The noteholders know now that they’ve got a problem, but not much more than that. Telephoning the chief financial officer of this company, an electrical power retailer, only reached a genuinely odd voice mail greeting last week.

After the first ring, suggesting there was no intention of ever picking up the phone, his voice tells investors with questions to go to the Securities and Exchange Commission website, even helpfully spelling Aspirity to make a search for filings easier.

There was nothing reassuring to be found there. Investors in these notes, about $30.5 million as of late April, could have found in a filing now nearly a month old that the subordinated note program had been “suspended,” with no further interest payments or redemptions to be made.

One reason for the suspension was the reaction by noteholders to the “going concern” disclosure in the company’s last audited financial statements, that familiar language of accountants expressing substantial doubt whether the company can stay in business.

There was even more bad news. The company was owed millions of dollars by another entity controlled by the chairman and controlling owner of Aspirity, Timothy Krieger. The auditors seem to have decided that this loan to the chairman’s other company wasn’t really worth much after all, reclassifying this asset as a “contra-equity.”

That basically put a big minus sign in front of a big number in the owner’s equity part of the balance sheet. That’s how $19 million in total assets withered to $2 million.

Now you can understand why the CFO, Wiley H. Sharp III, was staying away from the phone. And no, he did not return calls. Krieger didn’t either.

To be fair it’s not clear what more could be said. In fact it’s a complete head-scratcher how any mom-and-pop saver could’ve thought loaning money to Aspirity was a good idea.

The company was once known as Twin Cities Power Holdings, but as a result of corporate restructurings the business being funded recently by noteholders was basically a start-up company selling electric power to homeowners. The plan didn’t call for breaking even on a cash basis until sometime next year.

As of the last reported quarter, retail electricity revenue was not quite $800,000.

One of the things the restructured company retained was the noteholder program, which had been around for several years. According to the latest annual filing, more than $42 million of notes had been sold through April, directly to investors.

You can be sure it wasn’t Connecticut hedge funds or mutual fund giants like Fidelity buying these things, but ordinary investors. What they were doing, through the notes, is loaning money to a speculative company, in increments as small as $1,000 and for as short as three months or as long as 10 years.

They were called renewable notes because, unless notified otherwise, the company would automatically “renew” them when they matured. The unsecured part of the description is pretty straightforward, as there would be no claim on assets to help repay them. There were subordinated, too, meaning other lenders like a bank would get paid first.

So investors could loan money to an unproven electric power retailer not that close to making money, taking no more than a glorified IOU and standing way back in any line for repayment.

And if investors thought they understood all of that, it’s still unclear how they could have gotten comfortable with the risk in the other side of the business, called Aspirity Financial.

Aspirity Financial was a lender, but as best can be determined with just one borrower. That’s Timothy Krieger, also the chairman of Aspirity and its controlling owner.

His company was called Krieger Enterprises, with energy trading and other business interests. It had been spun off from Aspirity, with Aspirity ending up financing Krieger Enterprises. At year-end, the loan was about $15 million, but when investors in the RUSNs downloaded the annual report in late April they wouldn’t have been able to find that loan listed among the assets. It would have also been puzzling to see just over $2 million in assets as of the end of the year when there had been $19.3 million in September.

Well, that loan was now listed down in the shareholders equity section, a $15 million negative number. That pushed total owners’ equity into a deficit of $31.3 million.

As to what happened, it’s hard to top the way the last annual SEC filing put it: “Due to recent losses, the historical volatility of [Krieger Enterprises’] primary business of wholesale electricity trading, and the level of assets in the business, there is no longer significant evidence of collectability of all amounts owed.”

It’s a fairly safe bet that buyers of these notes didn’t fully understand all of their risk before they invested. It’s also fair to conclude that the people in charge at the company selling the notes had to be counting on the fact that investors didn’t quite get it.

Let’s be clear. The only real appeal here was what appeared to be great interest rates. Two-year Treasury notes are still yielding less than 1.4 percent, and someone could put $25,000 into Aspirity notes for two years and get an annual rate of 13 percent, compounded daily.

You can almost picture the middle-class savers punching that number into those website calculators for the traditional rule of 72 to see how many years it would take at 13 percent to double their money.

One thing that seems to be missing from these personal finance websites, though, is a place to calculate what would happen if the investor never got their original investment back.