An alternative to high-yield bank savings accounts are money market funds held in brokerage accounts. Although both money market funds and savings accounts can change their interest rates paid at any time, comparing their actual returns can be confusing.
Money market funds usually report their 7-day annualized yield (also listed as just yield, or 7-day yield), which takes the interest paid net of expenses for the last 7 days and assumes that this average continues over an entire year. Compounding is not taken into account, so the 7-day yield should be compared to a bank account’s annual percentage rate (APR).
Some funds also list the 7-day effective yield (also listed as compound yield), which does take into account compounding via the reinvesting of dividends. So the 7-day effective yield should be compared to annual percentage yield (APY).
Since banks usually advertise APY, you can convert if needed using this APY to APR calculator. Keep in mind that since these are moving 7-day averages, the numbers given will change from week to week.
Other Types of Money Market Funds
The above comparison is meant for the most common “taxable” money market funds, which are taxalbe on both federal and state levels just like a bank’s savings account. In addition to these, there are a variety of specific types of funds like Treasury funds (exempt from state income tax) and municipal tax-exempt funds (exempt from federal income tax), and state-specific municipal funds (exempt from both fed and state taxes) that offer special tax consideration.
In this case, you can use a tax-equivalent yield calculator to complete the comparison.
But Is The Risk The Same?
While not eligible to be FDIC-insured as they are not banks, money market funds do have to follow strict guidelines as to maintain the highest credit quality and lowest volatility of the underlying investments. The share is always kept at $1. Due to the recent concerns with mortgage-backed bonds, Fool.com recently asked Is Your Money Market Fund Safe? In my opinion, the risk is a definitely higher than a bank account, but if you hold your money market funds from a respected firm like Vanguard or Fidelity, I would sleep just as soundly, as these companies would repay the funds with their own assets rather than let them falter.
There are also other practical differences between specific banks and specific money market funds, which I am ignoring here.