What it means
The instrument itself is genuinely long term, usually a municipal bond or a corporate preferred share maturing twenty or thirty years out. What made it unusual was the reset mechanism, a Dutch auction held every few weeks that fixed the coupon for the next short period.
In a Dutch auction the rate starts high and falls until enough bids clear the whole amount offered, so the clearing rate is the lowest rate at which every share finds a buyer. Issuers liked the structure because they paid short-term rates on long-term money, and investors liked it because they believed they could exit at any auction.
The weakness sat in what happened when buyers did not turn up. If bids failed to cover the amount offered for sale, the auction failed, existing holders were stuck with securities they could not sell, and the rate jumped to a contractual maximum written into the offering documents.
That maximum rate is the part finance teams should study before anything else. A failed auction converts cheap short-term funding into expensive long-term funding overnight, and for an issuer with several hundred million outstanding the annual cost swing runs into tens of millions of dollars.
After the market seized up during the 2008 credit crisis, most issuers refinanced out of these structures and the sector shrank dramatically. The lasting lesson is about liquidity assumptions, because an instrument is only as short term as somebody else's continuing willingness to buy it.
In practice
Real-world examples.
Example
A university treasury holds $25,000,000 of auction rate securities in what its policy describes as the cash portfolio. When auctions fail, the holdings cannot be sold at any price and the university has to arrange a bank facility to fund payroll and construction commitments it had expected the securities to cover.
Example
A city water authority funds a treatment plant with auction rate debt because the reset rates are cheaper than fixed-rate bonds. After a run of failed auctions pushes its rate to the contractual maximum, it refinances the whole issue into fixed-rate bonds, paying a higher headline coupon in exchange for certainty.
Example
A corporate finance team reviewing its investment policy notices that an instrument classified as a cash equivalent has a maturity twenty-eight years away. It reclassifies the holding as a long-term investment, which reduces reported working capital but gives the board an honest picture of what can actually be turned into cash.
Formula
Calculation
Interest for one reset period = principal x clearing rate x (days in period / 360)
An issuer has $10,000,000 of auction rate securities with a 28-day reset period, calculated on an actual over 360 day basis.
A normal auction clears at 3.6%:
$10,000,000 x 0.036 = $360,000 a year.
$360,000 x 28 / 360 = $28,000 for the 28-day period.
The next auction fails, so the rate moves to the contractual maximum of 12%:
$10,000,000 x 0.12 = $1,200,000 a year.
$1,200,000 x 28 / 360 = $93,333.33 for the 28-day period.
Extra cost for that single period = $93,333.33 - $28,000 = $65,333.33.
If auctions keep failing for a full year, the annual interest cost rises from $360,000 to $1,200,000, an increase of $840,000 on the same $10,000,000 of borrowing. The principal is unchanged, the maturity is unchanged, and nothing about the issuer's credit has necessarily changed; only the willingness of buyers to show up has.Case study
Seen in the real world.
Vellmore Regional Health Trust is a fictional not-for-profit hospital group created solely to illustrate this concept. It funded a new wing with $60,000,000 of auction rate debt at an average clearing rate of 3.5%, giving an annual interest cost of $2,100,000, comfortably below the fixed-rate alternative it had been quoted.
When the auctions for its securities failed, the rate reset to the documented maximum of 10%. The annual cost became $6,000,000, an increase of $3,900,000 that had never appeared in any budget. The trust's investment portfolio was hit from the other direction at the same time, because it also held $12,000,000 of similar securities issued by other bodies and could not sell them to meet the higher payments.
In this illustrative case, the trust refinanced within four months into fixed-rate bonds at 5.2%, costing $3,120,000 a year, which was more than the original plan but far less than the penalty rate. The finance committee's conclusion was blunt and worth borrowing: an instrument should be classified by the date its principal is due, not by how often its interest rate happens to change.
Watch out
Common mistakes.
- Classifying auction rate securities as cash equivalents. The reset frequency is short but the maturity is decades away, and liquidity depends entirely on other buyers appearing at each auction.
- Ignoring the maximum rate clause when issuing. That single number defines your worst case, and issuers who never modelled it were the ones most badly caught when auctions failed.
- Assuming a failed auction means the issuer has defaulted. A failure means there were not enough buyers, and the issuer normally keeps paying interest, just at a much higher rate.
Questions
People also ask.
How is the reset rate actually determined?
Through a Dutch auction in which the rate falls until the total bids cover the securities being sold, with the last accepted rate applied to every holder for the coming period.
Why did issuers use them instead of ordinary long-term bonds?
They allowed long-dated money to be raised at short-term interest rates, which typically saved a meaningful margin every year while auctions kept clearing.
Do these securities still exist?
A much smaller market remains, mostly in older municipal and student loan issues, and most issuers refinanced into variable rate demand notes or fixed-rate bonds instead.
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