Originally Posted by redtop43

You are letting the tail wag the dog here.

I am old enough to remember when I was getting 15% or so on my money market fund. In those days my wife had some very high medical expenses, and I would try to get the insurance company to pay me as quickly as possible and wait as long as I could to pay the provider. $5000 for a month at 15% was $62.50.

That said, I'll start by saying that a money market fund or online saving account will pay yields comparable to T-bills but with much less complication.

But again, you're letting the tail wag the dog.

Simon GC fees are 79 basis points. WM fees run 9 basis points for MO's and 8 for bill payments. Using a 2% cashback card (I know you're doing this for miles) gives a profit of 110 basis points on each turnaround. By comparison, 2.4% annual is 20 basis points per month, so the potential interest - taxable, remember - is less than 20% of the basic profit.

But (and it's a huge but):

Your proposed strategy locks up your CC credit limit for basically two months. You're getting maybe 40 basis points of interest, but if you paid off the CC immediately and bought more GC's, you'd get the 110 basis points all over again. Not a great trade.

I "cycle" my credit cards. I know many people think that's high-risk, and I have had some accounts shut down. But I can use the same dollar of credit limit 3-4 times a month, so a $10K credit limit will let me earn $330-$440 a month.

Now, if you perceive yourself as having a cap on the time and effort you want to invest in this hobby, you could certainly optimize things by buying the GC's right after the statement close date, buying the MO's quickly, and waiting to pay the CC bill. (Bill payments obviously wouldn't work.)

But I think it's an inefficient use of your CC credit limits.