Table of Contents
Money market instruments are short-term debt securities with original maturities of one year or less that combine high credit quality with exceptional liquidity, traded primarily in an over-the-counter wholesale market among banks, corporations, government entities, broker-dealers, and institutional investors to satisfy short-term funding and cash management needs.
They represent the most liquid segment of the fixed income market — the instruments closest to cash on the liquidity spectrum — and serve as the raw material from which money market funds construct their portfolios, as the mechanism through which the Federal Reserve implements monetary policy, and as the primary tool through which corporations and financial institutions manage their daily cash positions.
The six primary money market instruments — Treasury bills, commercial paper, negotiable certificates of deposit, bankers' acceptances, repurchase agreements, and federal funds — are tested throughout the SIE and Series 7 examinations.
All money market instruments share three core characteristics that distinguish them from longer-term capital market instruments.
Original maturity of one year or less is the definitional boundary of the money market. Securities with maturities extending beyond one year — bonds, notes, debentures — belong to the capital market regardless of how much time remains until their maturity.
A bond with twenty-five years remaining to maturity has never been a money market instrument. A bond with six months remaining to maturity, while it trades in the money market, originated as a capital market instrument. The money market definition requires that the instrument was issued with a maturity of one year or less at the time of original issuance.
High credit quality protects the principal stability that money market investors require. Because these instruments are short-term and highly liquid, investors are unwilling to accept meaningful credit risk in exchange for yield — the primary return objective is preservation of capital and immediate liquidity, not yield maximisation.
SEC Rule 2a-7 under the Investment Company Act of 1940 reflects this priority by restricting money market fund portfolios to securities meeting specified credit quality thresholds — specifically, securities rated in the top two credit rating categories by at least one nationally recognised statistical rating organisation, or determined by the fund's board to present minimal credit risk.
High liquidity means these instruments can be quickly converted to cash at or near their face value, either through active secondary markets or through their approaching maturity. The very short time until maturity means that even without an active secondary market, the investor knows they will receive full face value within days or weeks.
Treasury bills — universally abbreviated T-bills — are short-term obligations of the United States government issued by the Department of the Treasury through the Bureau of the Fiscal Service under the authority of the Second Liberty Bond Act. They are the safest and most liquid money market instruments in the world, carrying the full faith and credit of the United States government, and they serve as the benchmark against which all other money market instruments are priced.
T-bills are issued in three standard maturities — four-week, thirteen-week, and twenty-six week — with fifty-two-week bills also auctioned. Four-week and thirteen-week bills are auctioned weekly on Monday. Twenty-six-week bills are also auctioned weekly. Fifty-two-week bills are auctioned every four weeks. All T-bill auctions are conducted using the single-price uniform auction method under 31 CFR Part 356, in which all winning competitive bids receive securities at the same yield — the highest yield at which the Treasury accepts bids — and non-competitive bidders receive that same yield automatically.
T-bills are issued at a discount to face value and pay no periodic coupon interest. The investor's return is the difference between the discounted purchase price and the face value received at maturity. A thirteen-week T-bill with a face value of one thousand dollars purchased at a discount for nine hundred and ninety dollars returns one thousand dollars at maturity — the ten dollar difference represents the interest earned. The discount yield is calculated differently from bond yields, using the bank discount method: discount yield equals the dollar discount divided by face value, multiplied by three hundred and sixty divided by days to maturity. This bank discount convention understates the true yield relative to bond equivalent yield — a distinction that appears on examinations.
Commercial paper is short-term unsecured promissory notes issued by large corporations with strong credit ratings to finance short-term operating needs — accounts receivable, seasonal inventory buildup, payroll — at interest rates below what bank loans would cost. Commercial paper is the primary instrument through which large corporations bypass the banking system entirely for short-term financing, accessing capital markets directly at market rates.
Commercial paper maturities range from one day to a maximum of two hundred and seventy days under the Securities Act of 1933 Section 3(a)(3) exemption, which exempts commercial paper from the registration requirement provided it has a maturity not exceeding two hundred and seventy days, is of the type not ordinarily purchased by the general public, and is issued to finance current transactions. Issuances with maturities of two hundred and seventy-one days or more lose the exemption and must be registered with the SEC.
Commercial paper is issued at a discount to face value — like T-bills — with no coupon. Only the most creditworthy issuers can access the commercial paper market because investors will not accept meaningful credit risk at these short maturities. General Electric, JPMorgan Chase, Toyota Motor Credit, and similarly creditworthy corporations are typical issuers. As confirmed by the Richmond Federal Reserve Bank's Instruments of the Money Market reference, corporations access the commercial paper market through dealers who resell the paper to investors, or through direct placement to large institutional investors without a dealer intermediary.
Asset-backed commercial paper — ABCP — is commercial paper issued by special purpose vehicles that purchase and hold pools of financial assets such as auto loans, credit card receivables, and trade receivables, using those assets as the economic backing for the paper. ABCP conduits were at the centre of the 2008 financial crisis when their underlying assets deteriorated, the conduits could no longer roll their maturing paper, and the commercial paper market seized. The Federal Reserve established the Commercial Paper Funding Facility in October 2008 to purchase ABCP and unsecured commercial paper directly, providing the market liquidity that private investors had withdrawn.
A negotiable certificate of deposit is a time deposit issued by a bank in large denominations — minimum one hundred thousand dollars, with most institutional transactions occurring in one million dollar minimum sizes — that can be sold in the secondary market before maturity. The negotiability distinguishes it from the standard retail certificate of deposit, which imposes early withdrawal penalties and cannot be freely transferred.
Negotiable CDs are issued by commercial banks, savings institutions, and foreign banks operating in the United States. They carry a fixed interest rate and maturity — typically ranging from one week to one year — and are priced in the secondary market at yields reflecting the issuing bank's credit quality relative to comparable-maturity T-bills. Because they carry bank credit risk rather than government credit risk, negotiable CDs yield somewhat more than T-bills of equivalent maturity.
The interest on negotiable CDs is subject to federal, state, and local income taxes, unlike Treasury bill interest which is exempt from state and local taxes under 31 U.S.C. 3124. Deposits in negotiable CDs are insured by the FDIC only up to the standard deposit insurance limit of two hundred and fifty thousand dollars per depositor per institution per ownership category — leaving the portion above that limit uninsured and therefore carrying bank credit risk for large institutional investors who routinely hold positions far exceeding the insurance limit.
A bankers' acceptance is a short-term time draft drawn by a corporation and accepted — guaranteed — by a bank, creating an unconditional obligation of the bank to pay the face value at maturity to whoever presents the instrument. They arise most frequently in international trade finance when an importing company draws a draft on its bank for the amount it owes a foreign seller, the bank accepts the draft — meaning it stamps it accepted and thereby guarantees payment — and the exporter can then sell the acceptance in the money market rather than waiting for the scheduled payment date.
Bankers' acceptances have maturities ranging from thirty to one hundred and eighty days, though the most common maturities are ninety days. Because they carry the credit of the accepting bank rather than the corporation that drew the draft, they are considered high-quality money market instruments. They are sold at a discount to face value and trade in an active secondary market among dealers and institutional investors.
The key examination distinction is that a bankers' acceptance is a two-name paper — both the company that drew the draft and the bank that accepted it are obligated to pay. The bank's acceptance transforms a corporate obligation into a bank-guaranteed instrument, substantially improving its credit quality and marketability.
A repurchase agreement — universally called a repo — is an economically equivalent transaction to a short-term collateralised loan, structured as a sale of securities today combined with a contractual agreement to repurchase those same securities at a specified higher price on a specified future date. The difference between the sale price and the repurchase price represents the interest paid by the borrower.
From the borrower's perspective — the dealer or financial institution initiating the transaction — the repo is a mechanism to obtain short-term financing by temporarily pledging securities as collateral. From the lender's perspective — the counterparty purchasing the securities and agreeing to sell them back — the repo is a mechanism to invest cash short-term in a fully collateralised transaction, earning interest while holding securities that provide protection against the borrower's default.
Overnight repos — with a repurchase date the following business day — are the most common, providing daily liquidity to both sides. Term repos extend for days, weeks, or up to several months. Open repos have no fixed term and can be terminated by either party with one day's notice. Repos are primarily collateralised by Treasury securities, agency securities, and mortgage-backed securities — the highest quality collateral that commands the lowest haircuts and tightest repo rates.
The Federal Reserve uses repos and reverse repos as its primary mechanism for managing bank reserves and the federal funds rate. When the Federal Reserve wishes to add temporary reserves to the banking system, it enters into repos — purchasing securities from dealers and agreeing to sell them back, temporarily injecting cash. When it wishes to drain reserves, it enters reverse repos — selling securities to dealers with agreements to repurchase them.
Federal funds are unsecured overnight loans between depository institutions with reserve accounts at Federal Reserve banks. Banks with excess reserves at the Federal Reserve lend those reserves to banks with reserve shortfalls, typically for one business day at the federal funds rate. Unlike most money market instruments, federal funds are not marketable securities — they are direct interbank loans whose terms are negotiated bilaterally between counterparties without a secondary market.
The federal funds market is the mechanism through which the Federal Reserve's monetary policy transmits into the broader financial system. The FOMC sets a target range for the federal funds rate — the interest rate at which these overnight interbank loans occur — and the Federal Reserve manages its balance sheet and operations to maintain the effective federal funds rate within that target range. Changes in the federal funds rate propagate through the yield curve, affecting all other money market rates and ultimately influencing the borrowing costs of corporations, homeowners, and consumers throughout the economy.
Money market mutual funds — whose entry on this site is already published — invest exclusively in money market instruments subject to the quality, maturity, and liquidity requirements of SEC Rule 2a-7 under the Investment Company Act of 1940. Rule 2a-7 restricts fund portfolios to securities with remaining maturities of thirteen months or less, requires a dollar-weighted average portfolio maturity of sixty days or less and a dollar-weighted average life of one hundred and twenty days or less, mandates minimum liquidity requirements of at least ten percent of assets in daily liquid assets and at least thirty percent in weekly liquid assets, and restricts investment to securities meeting specified credit quality criteria confirming minimal credit risk.
The Reserve Primary Fund's breaking of the buck in September 2008 — when its net asset value fell below one dollar per share after Lehman Brothers commercial paper it held became worthless — triggered massive institutional redemptions from prime money market funds and froze the commercial paper market. The subsequent reforms to Rule 2a-7 implemented by the SEC in 2010 and 2016 significantly tightened quality, maturity, and liquidity requirements and introduced floating NAV requirements for institutional prime money market funds, with further amendments adopted in 2023 requiring higher daily and weekly liquid asset minimums for non-government money market funds.
Money market instruments are tested on the SIE and Series 7 examinations in the context of money market fund portfolios, short-term fixed income, Federal Reserve monetary policy, and the characteristics distinguishing different money market instrument types.
The key points to retain are these.
Money market instruments are debt securities with original maturities of one year or less, high credit quality, and exceptional liquidity — the segment of the fixed income market closest to cash. Treasury bills are the benchmark — safest and most liquid — issued at a discount with four-week, thirteen-week, and twenty-six-week standard maturities through 31 CFR Part 356 auction procedures, with interest exempt from state and local taxes under 31 U.S.C. 3124.
Commercial paper is unsecured promissory notes issued by creditworthy corporations with maturities up to two hundred and seventy days — the maximum permitting the Securities Act Section 3(a)(3) registration exemption — issued at a discount and used to finance short-term operating needs.
Negotiable CDs are large-denomination bank time deposits with secondary market trading ability, carrying bank credit risk rather than government backing and fully taxable at all levels. Bankers' acceptances are bank-guaranteed time drafts arising from trade finance, carrying two-name paper credit of both the drawing corporation and the accepting bank, with maturities of thirty to one hundred and eighty days.
Repurchase agreements are economically equivalent to short-term collateralised loans — the borrower sells securities and agrees to repurchase them at a higher price — used extensively by dealers and the Federal Reserve for reserve management.
Federal funds are unsecured overnight interbank loans between depository institutions, not marketable securities, transacted at the federal funds rate that is the primary target of Federal Reserve monetary policy.
