Money Market funds and E*Trade

[zetta]

At previous brokerages that I've used, the default money market fund where cash is held has earned reasonable interest, so I've just used the default and not shopped around.

I'm finding that my cash in my E*Trade investment account is earning squat. (The E*Trade Bank savings and checking accounts are earning much better interest.) For psychological reasons I prefer to keep my emergency fund in a separate account from my savings account (which I use to save for semi-annual bills and vacations.)

Is there a way to invest my cash in a money market fund while still keeping it at E*Trade? Would I then have to pay for a trade each time I moved money to and from? Where do I find the fund?

[zetta]

After a little more searching on the E*Trade website, I find that there are 8 money market funds offered by JPMorgan that can be used as a "sweep" account within ETrade. The 7-day yields run from 1.47% to 4.18%. Anybody know how to convert 7-day yield to APR?

The best yield is currently in JPMorgan Federal Money Market Fund, Morgan Class. I can't tell if there are any minimum balances or other restrictions that would prevent me from choosing this one. Why would anybody pick one of the lower-yielding funds?

[zetta]

Now when I pull it up to show my husband, the yield for JPMorgan Federal Money Market Fund is quoted as 2.08%. Something is a little buggy to say the least...