DH has his "fun money" checking account with Chase. We have our joint checking and all of our savings with CapitalOne360. Chase sent him an offer to give us $125 if we open a savings account with $10k in it and leave it there for at least 6 months.
Right now, our E-fund is just over $10k. We're seriously considering opening the account with Chase, moving exactly $10k over there, and moving the $10,125 back in exactly 6 months. In CO360, $10k would make about $38 over 6 months, so we would be netting ~$87. We would continue to save in CO360 while we wait.
The only issue I can see coming up is if we actually needed the money in the next 6 months, we would forfeit the $125 and would only have the measly .01% interest we'd been accruing. Given that we're both in school with guaranteed assistantships/fellowships through the next two years and we have another $8k in savings for other purposes, I feel like that $36 bet is worth taking.
Just wanted to check with MM: am I missing anything here?
UPDATE: So I ended up reading the fine print. It turns out, there's nothing about actually keeping the $10k in the account for 6mo, just that the account has to be open that long. The minimum balance to have no fees is $300, so we could transfer $10k in, then $9825 out a couple weeks later once the $125 is deposited, and leave the remaining $300 in there for 6mo. This way we only lose about $3-4 in interest instead of $38. There are no closing fees (H had a savings account with them before and ended up closing it, and there were no fees. We'll check to be sure this hasn't changed).
Sounds like an even better idea now...
Re: Can you think of a good reason not to do this? (UPDATED)
I think we would probably do that. And honestly, having your emergency fund being a little hard to access is a good thing- you want the money readily available so it is there in an emergency, but you don't want to be tempted to tap into for a non-emergency. Depending upon the rates after the first 6 months, you may just want to leave it there.
one thing you didn't mention- is the savings account free- if there are fees associated with it, that would probably change my answer and make it less worth it.
yeah, the rate at Chase is 0.01% compared to our 0.75%, so we will definitely be moving it back immediately after 6 months. We really don't have a problem not pulling from our E-fund, so the accessibility isn't an issue here.
I haven't looked into the account too carefully yet, but I believe it's free. His checking account is free with a minimum direct deposit, and this would be a linked account. In my experience, that's always been free. We will check that before we do it, thanks for pointing that out.

"You know you're in love when you don't want to fall asleep because reality is finally better than your dreams." - Dr. SeussVerify that there are no account closing fees (even after that waiting period you mentioned) first before doing it.