# United States Treasury Money Mutual Fund: Meaning, How It Works

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## What Is a United States Treasury Money Mutual Fund?

A United States Treasury money mutual fund is a [mutual fund](https://www.investopedia.com/terms/m/mutualfund.asp) that pools money from investors to purchase low-risk government securities. A United States Treasury money mutual fund is a type of mutual fund that invests primarily or exclusively in U.S. government debt, such as [Treasury bills](https://www.investopedia.com/terms/t/treasurybill.asp) and repurchase agreements. U.S. Treasury money mutual funds are a leading investment for investors seeking to preserve principal or invest cash temporarily.

### Key Takeaways

*   A U.S. Treasury money mutual fund invests in low risk and highly liquid investments such as U.S. Treasury bills.
*   These funds are ideal for investors seeking stable investments that preserve invested principal.
*   Money mutual funds are regulated by the Securities and Exchange Commission (SEC), which stipulates rules regarding maturity, credit quality, and liquidity of securities.

## Understanding a United States Treasury Money Mutual Fund

U.S. Treasury money mutual funds are one of the industry’s best low-risk investments. These mutual funds typically invest in U.S. Treasury bills and are highly stable and liquid. These funds are generally classified as either [money market funds](https://www.investopedia.com/terms/m/money-marketfund.asp) or found in low-risk [fixed income](https://www.investopedia.com/terms/f/fixedincome.asp) categories. Treasury bills are secured by the full faith and credit of the United States Treasury, which helps to make these portfolios reliable sources of low-risk returns due to the country’s developed economy and political stability.

## U.S. Government Money Market Funds

Money managers across the industry offer money market mutual funds that fully invest in U.S. Treasuries. U.S. government money market mutual funds follow standard accounting principles that help to keep their net asset value at $1 per share at [amortized](https://www.investopedia.com/terms/a/amortization.asp) cost rather than market value. These funds register as money market funds and are governed primarily by [Rule 2a-7](https://www.investopedia.com/articles/mutualfund/10/a-safer-money-market-2a7.asp) of the Investment Company Act of 1940.﻿﻿

The rule stipulates the type of quality the funds can invest in, ensuring that only the highest-rated debt is included. Rules cover the [maturity](https://www.investopedia.com/terms/m/maturity.asp), credit quality, and [liquidity](https://www.investopedia.com/terms/l/liquidity.asp) of the securities invested. Under the rule, in regards to maturity, the average dollar-weighted maturity cannot exceed 60 days. Under liquidity rules, 10% of assets must be able to be converted into cash within one day, 30% within five days, and no more than 5% can be held in securities that take longer than a week to convert into cash.﻿﻿

Rules and regulations for money market funds have been revised to provide even greater security for investors since the [2008 financial crisis](https://www.investopedia.com/articles/economics/09/financial-crisis-review.asp) when the popular Reserve Primary Fund [broke the buck](https://www.investopedia.com/terms/b/breaking-the-buck.asp) by falling below its $1 net asset value.﻿﻿

Often, U.S. government money market funds managed by brokerage service providers will be offered as cash [sweep](https://www.investopedia.com/terms/s/sweepaccount.asp) options or no-transaction-fee funds. Some of the most popular U.S. government money market funds include:

[Vanguard](https://www.investopedia.com/vanguard-review-4587932) Treasury Money Market Fund (VUSXX)

[Fidelity](https://www.investopedia.com/fidelity-review-4587897) Treasury Only Money Market Fund (FDLXX)

American Century Capital Preservation Fund (CPFXX)

## U.S. Government Mutual Funds

Many [investment managers](https://www.investopedia.com/terms/i/investment-manager.asp) across the industry also offer U.S. government mutual funds that are not characterized by the money market designation but offer many of the same benefits. These funds can offer slightly higher returns than money market funds with generally the same risk. U.S. government mutual funds can include short-, intermediate-, and [long-term](https://www.investopedia.com/terms/l/longterm.asp) durations, with longer-term durations potentially offering enhanced returns. Some of the most popular U.S. government mutual funds include:

*   Eaton Vance Short Duration Government Income Fund (EALDX)
*   Commerce Short Term Government Fund (CFSTX)
*   Federated Hermes Total Return Government Bond Fund (FTRGX)
*   Fidelity Intermediate Treasury Bond Index Fund (FUAMX)
*   Vanguard Extended Duration Treasury Index Fund (VEDTX)
*   Fidelity Long-Term Treasury Bond Index Fund (FNBGX)

> **Article Sources**
>
> 1.  U.S. Government Publishing Office. "[§270.2a-7 Money market funds](https://www.ecfr.gov/cgi-bin/text-idx?SID=c91f600a3a1b505d41e46a06d176432a&mc=true&node=se17.4.270_12a_67&rgn=div8)." Accessed Feb. 7, 2021.
>     
> 2.  U.S. Securities and Exchange Commission. "[Reserve Primary Fund Distributes Assets to Investors](https://www.sec.gov/news/press/2010/2010-16.htm)." Accessed Feb. 7, 2021.