What it means
The money market is not a physical place; it is a network of banks, funds, governments and large companies trading short-dated debt with each other. The defining feature is time, because everything traded matures within a year and much of it matures within days.
For a business, the money market matters because cash sitting in a current account usually earns close to nothing. Moving surplus balances into short-dated instruments turns idle money into a small but real income stream without locking it away for long.
The instruments themselves are deliberately plain. Treasury bills are short-term government debt sold at a discount to face value, and commercial paper is unsecured short-term borrowing issued by large companies.
Certificates of deposit are time deposits issued by banks that pay a fixed rate until a set maturity date. Most smaller companies meet the money market indirectly, through a money market fund offered by their bank or broker.
The fund pools cash from many investors, buys a spread of short-dated instruments and pays out the blended yield after a management fee, so the treasurer never has to buy a single bill directly. The nuance worth remembering is that low risk does not mean no risk.
Money market funds are not bank deposits and are generally not covered by deposit insurance, so in a severe credit squeeze a fund can dip below its target value or restrict withdrawals.
In practice
Real-world examples.
Example
A software company raises $12,000,000 and knows it will spend the money over two years. The finance director sweeps $8,000,000 into a money market fund yielding around 4%, keeping the rest in the operating account, which adds several hundred thousand dollars of interest income across the funding runway.
Example
A construction firm invoices a large client and receives $1,500,000 sixty days before the matching subcontractor payments fall due. Rather than leaving the balance idle, it buys 60-day commercial paper and earns interest on money that was always destined to leave the business.
Example
A retailer with heavy December sales holds unusually large balances in January. Its bank sweeps anything above a $400,000 working buffer into an overnight money market account each evening and returns it every morning, so trading is never constrained but the surplus is never idle.
Formula
Calculation
Interest earned = principal x annual yield x (days held / 365)
A distribution company has $2,000,000 of surplus cash that it will not need for a month, and its money market fund is quoting an annualised yield of 4.5%. A full year at that rate would earn $2,000,000 x 0.045 = $90,000. Scaling that to the 30 days the cash is actually invested gives $90,000 x (30 / 365) = $7,397. Left in a current account paying nothing, the same $2,000,000 would have earned $0, so the treasurer picks up roughly $7,397 for a single instruction and almost no loss of access to the money.Case study
Seen in the real world.
Northgate Textiles is a fictional mid-sized fabric wholesaler used here purely as an illustrative case. Its cash balance swings between $1,500,000 and $4,000,000 across the season, and for years the whole amount sat in a current account paying nothing because nobody wanted to risk being short during a restocking week.
A new controller mapped six months of daily balances and found that the account never fell below $1,500,000. She left $1,200,000 in the operating account as a buffer and moved the rest into a money market fund with same-day access, which at an average balance of $1,400,000 and a 4.4% yield produced about $61,600 of interest over a full year.
The illustrative lesson is not that the yield was large in itself, but that it required no new customers, no extra staff and no reduction in operating flexibility. It came entirely from noticing that a portion of the cash was permanently unused.
Watch out
Common mistakes.
- Treating a money market fund as identical to a bank deposit, when it is an investment product without deposit insurance and with a value that can, in rare conditions, fall.
- Chasing the highest quoted yield without reading what the fund actually holds, since a slightly higher return often reflects lower-quality commercial paper rather than better management.
- Moving so much cash into the money market that the operating account cannot cover payroll or a surprise supplier payment, which turns a small interest gain into an expensive overdraft.
Questions
People also ask.
Is the money market the same as the stock market?
No, the stock market trades ownership in companies with no maturity date, while the money market trades short-term debt that matures within a year.
How quickly can I get my money back?
Most money market funds offer same-day or next-day access, but you should confirm the cut-off time and any notice period before you rely on it for payroll week.
Does a small business really need this?
If your balance regularly sits above the level you actually use, then yes, because the interest is close to free money, though below roughly $250,000 the admin effort may outweigh the return.
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