This is a site to answer tax questions not investment questions. Go on any reputable financial company's web site or contact a financial adviser for recommendations. There may be other money market funds that have better results than the one you are currently invested in. Almost any other investment will have more risk.
This website does indeed entertain investment discussion so you have come to the right place.
Your first consideration should be to maintain 6-12 months’ worth of ready cash in the form of a money market fund or bank savings account to cover a possible job loss and/or unexpected expenses.
Once you have that covered, great way to determine your best long-term investment strategy is to take a short asset allocation/risk tolerance test at the following link. https://personal.vanguard.com/us/FundsInvQuestionnaire
This test will determine your optimal mix of stocks, bonds, and cash reserves given your risk tolerance and temperament.
If you decide to implement the results, you will see Vanguard’s toll-free phone number on the Suggested Allocation page.
Of course. you also have the option of consulting a financial advisor. Your best bet may be an individual who holds a Certified Financial Planner (CFP) designation who charges a fee for advice rather than commissions for selling products.
To answer, more info would be needed. What other investments do you have? Savings? If you have other funds elsewhere, stick this in an index fund (I prefer Vanguard VTSAX fund). If you don't have anything else set aside then try the VBTLX which is Vanguards Bond index fund. But I agree with others that say to have a 6-12 months savings FIRST before other money for investments. If you research index funds they have good reputations, even if riskier than a mutual fund.
An alternate strategy to consider once a 6-12 months cash cushion is created is to pay down installment and credit card debt early.
For instance, if you prepay a loan with 12% interest, you have effectively earned a guaranteed 12% return. You have no such guarantee in the stock and bond markets.
As a bonus, becoming debt free can be a real stress reliever.
I realize the original question is several months old. The global economy has changed a bit since then and the geopolitical situation has deteriorated even further.
I am a retiree with no income other than my investments (and a pittance from Social Security). In anticipation of a recession, I maintain 2 years of living expenses - a lot more than the $12k in the OP - in cash and cash equivalents.