26 CFR §1.148-10

1. (a)Abusive arbitrage device
   1. (1)In general. Bonds of an issue are arbitrage bonds under section 148 if an abusive arbitrage device under paragraph (a)(2) of this section is used in connection with the issue. This paragraph (a) is to be applied and interpreted broadly to carry out the purposes of section 148, as further described in § 1.148-0. Except as otherwise provided in paragraph (c) of this section, any action that is expressly permitted by section 148 or §§ 1.148-1 through 1.148-11 is not an abusive arbitrage device (e.g., investment in higher yielding investments during a permitted temporary period under section 148(c)).
   2. (2)Abusive arbitrage device defined. Any action is an abusive arbitrage device if the action has the effect of—
      1. (i)Enabling the issuer to exploit the difference between tax-exempt and taxable interest rates to obtain a material financial advantage; and
      2. (ii)Overburdening the tax-exempt bond market.
   3. (3)Exploitation of tax-exempt interest rates. An action may exploit tax-exempt interest rates under paragraph (a)(2) of this section as a result of an investment of any portion of the gross proceeds of an issue over any period of time, notwithstanding that, in the aggregate, the gross proceeds of the issue are not invested in higher yielding investments over the term of the issue.
   4. (4)Overburdening the tax-exempt market. An action overburdens the tax-exempt bond market under paragraph (a)(2)(ii) of this section if it results in issuing more bonds, issuing bonds earlier, or allowing bonds to remain outstanding longer than is otherwise reasonably necessary to accomplish the governmental purposes of the bonds, based on all the facts and circumstances. Whether an action is reasonably necessary to accomplish the governmental purposes of the bonds depends on whether the primary purpose of the transaction is a bona fide governmental purpose (e.g., an issue of refunding bonds to achieve a debt service restructuring that would be issued independent of any arbitrage benefit). An important factor bearing on this determination is whether the action would reasonably be taken to accomplish the governmental purpose of the issue if the interest on the issue were not excludable from gross income under section 103(a) (assuming that the hypothetical taxable interest rate would be the same as the actual tax-exempt interest rate). Factors evidencing an overissuance include the issuance of an issue the proceeds of which are reasonably expected to exceed by more than a minor portion the amount necessary to accomplish the governmental purposes of the issue, or an issue the proceeds of which are, in fact, substantially in excess of the amount of sale proceeds allocated to expenditures for the governmental purposes of the issue. One factor evidencing an early issuance is the issuance of bonds that do not qualify for a temporary period under § 1.148-2(e)(2), (e)(3), or (e)(4). One factor evidencing that bonds may remain outstanding longer than necessary is a term that exceeds the safe harbors against the creation of replacement proceeds under § 1.148-1(c)(4)(i)(B). These factors may be outweighed by other factors, such as bona fide cost underruns, an issuer's bona fide need to finance extraordinary working capital items, or an issuer's long-term financial distress.
2. (b)Consequences of overburdening the tax-exempt bond market
   1. (1)In general. An issue that overburdens the tax-exempt bond market (within the meaning of paragraph (a)(4) of this section) is subject to the following special limitations—
      1. (i)Special yield restriction. Investments are subject to the definition of materially higher yield under § 1.148-2(d) that is equal to one-thousandth of 1 percent. In addition, each investment is treated as a separate class of investments under § 1.148-5(b)(2)(ii), the yield on which may not be blended with that of other investments.
      2. (ii)Certain regulatory provisions inapplicable. The provisions of § 1.148-5(c) (relating to yield reduction payments) and § 1.148-5(e) (2) and (3) (relating to recovery of qualified administrative costs) do not apply.
      3. (iii)Restrictive expenditure rule. Proceeds are not allocated to expenditures unless the proceeds-spent-last rule under § 1.148-6(d)(3)(i) is satisfied, applied by treating those proceeds as proceeds to be used for restricted working capital expenditures. For this purpose, available amount includes a reasonable working capital reserve as defined in § 1.148-6(d)(3)(iii)(B).
   2. (2)Application. The provisions of this paragraph (b) only apply to the portion of an issue that, as a result of actions taken (or actions not taken) after the issue date, overburdens the market for tax-exempt bonds, except that for an issue that is reasonably expected as of the issue date to overburden the market, those provisions apply to all of the gross proceeds of the issue.
3. (c)Anti-abuse rules on excess gross proceeds of advance refunding issues
   1. (1)In general. Except as otherwise provided in this paragraph (c), an abusive arbitrage device is used and bonds of an advance refunding issue are arbitrage bonds if the issue has excess gross proceeds.
   2. (2)Definition of excess gross proceeds. Excess gross proceeds means all gross proceeds of an advance refunding issue that exceed an amount equal to 1 percent of sale proceeds of the issue, other than gross proceeds allocable to—
      1. (i)Payment of principal, interest, or call premium on the prior issue;
      2. (ii)Payment of pre-issuance accrued interest on the refunding issue, and interest on the refunding issue that accrues for a period up to the completion date of any capital project for which the prior issue was issued, plus one year;
      3. (iii)A reasonably required reserve or replacement fund for the refunding issue or investment proceeds of such a fund;
      4. (iv)Payment of costs of issuance of the refunding issue;
      5. (v)Payment of administrative costs allocable to repaying the prior issue, carrying and repaying the refunding issue, or investments of the refunding issue;
      6. (vi)Transferred proceeds that will be used or maintained for the governmental purpose of the prior issue;
      7. (vii)Interest on purpose investments;
      8. (viii)Replacement proceeds in a sinking fund for the refunding issue;
      9. (ix)Qualified guarantee fees for the refunding issue or the prior issue; and
      10. (x)Fees for a qualified hedge for the refunding issue.
   3. (3)Special treatment of transferred proceeds. For purposes of this paragraph (c), all unspent proceeds of the prior issue as of the issue date of the refunding issue are treated as transferred proceeds of the advance refunding issue.
   4. (4)Special rule for crossover refundings. An advance refunding issue is not an issue of arbitrage bonds under this paragraph (c) if all excess gross proceeds of the refunding issue are used to pay interest that accrues on the refunding issue before the prior issue is discharged, and no gross proceeds of any refunding issue are used to pay interest on the prior issue or to replace funds used directly or indirectly to pay such interest (other than transferred proceeds used to pay interest on the prior issue that accrues for a period up to the completion date of the project for which the prior issue was issued, plus one year, or proceeds used to pay principal that is attributable to accrued original issue discount).
   5. (5)Special rule for gross refundings. This paragraph (c)(5) applies if an advance refunding issue (the series B issue) is used together with one or more other advance refunding issues (the series A issues) in a gross refunding of a prior issue, but only if the use of a gross refunding method is required under bond documents that were effective prior to November 6, 1992. These advance refunding issues are not arbitrage bonds under this paragraph (c) if—
      1. (i)All excess gross proceeds of the series B issue and each series A issue are investment proceeds used to pay principal and interest on the series B issue;
      2. (ii)At least 99 percent of all principal and interest on the series B issue is paid with proceeds of the series B and series A issues or with the earnings on other amounts in the refunding escrow for the prior issue;
      3. (iii)The series B issue is discharged not later than the prior issue; and
      4. (iv)As of any date, the amount of gross proceeds of the series B issue allocated to expenditures does not exceed the aggregate amount of expenditures before that date for principal and interest on the series B issue, and administrative costs of carrying and repaying the series B issue, or of investments of the series B issue.
4. (d)Examples. The provisions of this section are illustrated by the following examples:
5. (e)Authority of the Commissioner to prevent transactions that are inconsistent with the purpose of the arbitrage investment restrictions. If an issuer enters into a transaction for a principal purpose of obtaining a material financial advantage based on the difference between tax-exempt and taxable interest rates in a manner that is inconsistent with the purposes of section 148, the Commissioner may exercise the Commissioner's discretion to depart from the rules of § 1.148-1 through § 1.148-11 as necessary to reflect the economics of the transaction to prevent such financial advantage. For this purpose, the Commissioner may recompute yield on an issue or on investments, reallocate payments and receipts on investments, recompute the rebate amount on an issue, treat a hedge as either a qualified hedge or not a qualified hedge, or otherwise adjust any item whatsoever bearing upon the investments and expenditures of gross proceeds of an issue. For example, if the amount paid for a hedge is specifically based on the amount of arbitrage earned or expected to be earned on the hedged bonds, a principal purpose of entering into the contract is to obtain a material financial advantage based on the difference between tax-exempt and taxable interest rates in a manner that is inconsistent with the purposes of section 148.
6. (f)Authority of the Commissioner to require an earlier date for payment of rebate. If the Commissioner determines that an issue is likely to fail to meet the requirements of § 1.148-3 and that a failure to serve a notice of demand for payment on the issuer will jeopardize the assessment or collection of tax on interest paid or to be paid on the issue, the date that the Commissioner serves notice on the issuer is treated as a required computation date for payment of rebate for that issue.
7. (g)Authority of the Commissioner to waive regulatory limitations. Notwithstanding any specific provision in §§ 1.148-1 through 1.148-11, the Commissioner may prescribe extensions of temporary periods, larger reasonably required reserve or replacement funds, or consequences of failures or remedial action under section 148 in lieu of or in addition to other consequences of those failures, or take other action, if the Commissioner finds that good faith or other similar circumstances so warrant, consistent with the purposes of section 148.