Morningstar U.K. asks, "Should You Invest in a Money Market Fund?" Morningstar's Mark Preskett explains in the video, "So, a money market fund would generally in highly liquid cash instruments with very short maturities, and they're typically seen as one of the safest forms of investments you can make.... There's a variety of instruments that a money market manager has at its disposal.... The safest are T-bills. These are issued by the U.K. Government's debt management office. Every week, they issue one-month, three-month and six-month paper and generally, the return you receive is linked to the Bank of England base rates." He adds, "There's also the specialist money market instruments that are issued by banks. So, certificate of deposits, commercial paper and time deposits. And generally, there the return is linked to the credit rating of the issuing bank. And there are other instruments like covered bonds, short-term credit and even asset-backed securities which are used by some managers to enhance yields." When asked about returns, he comments, "Generally, you should frame it around the Bank of England base rates, which is currently 0.75%. And then, you should look at the credit rating of the fund.... Also, duration or maturity, how long they're lending, how long the paper that they're buying. And finally, fees. That's probably the easiest way to see what return you're likely to get, especially in this low-yielding environment. So, a fund Royal London Short Term Money Market has ... an ongoing charge of around 10 basis points. So, when you're getting 75 basis points, you're giving back around 10 to the fund manager. By contrast, BlackRock Cash is another well-known fund out there, has a 32 basis point ongoing charge, which you know, eats into around half of your return. And you can really see that in the return profile of the two funds."