Money market funds invest in short-term debt instruments (usually maturities under one year) issued by governments or large institutions, seeking to preserve capital and offer near-immediate liquidity, with a return tied to official interest rates.
Risk profile
They're among the lowest-risk products within investment funds, although they aren't guaranteed like a deposit: their value can fluctuate slightly, especially in fast-changing interest-rate environments.
When they make sense
They're typically used as a temporary parking spot for liquidity (an emergency cushion, or money waiting for another investment), not as a long-term growth vehicle, since their expected return tends to be similar to that of Treasury bills or an interest-bearing account.