I keep a good portion of my futures trading account in banks earning ~ 1% interest (it comes to a good chunk of cash for larger accounts at the end of the year). And I transfer funds into the FCM as needed for routine drawdowns so that I do not have to decrease leverage. The banks I've encountered only process wire transfers once a day, near the end of the day, at about 4 p.m. ET. And the cut-off time to request the wire is about 3 p.m. So, if you want to wait for nearing the market's RTH close to decide whether or not to transfer additional funds to your FCM, and you initiate the wire at ~ 3:30 p.m. on Monday, your funds won't be sent until 4 p.m. on Tuesday, and maybe won't be available to be utilized at your FCM until Wednesday. And that's too long. There's no bank I've seen that processes wires more than once a day (and near the end of the day). Is there any bank that processes outgoing wires at least twice a day, say at 10 a.m. and 4 p.m.? Is there any method of moving money faster?
If you want to move money "now", then the only way to do it is via RTGS, otherwise if you do it via DNS then you'll be dependent on the clearing cycle's net settlement timeframes which can vary from hours to days depending on the protocols in place in your jurisdiction. RTGS has the added benefit of being a final and irrevocable payment mechanism because it is cleared via the central bank's books (which has the added bonus of removing all areas of settlement and credit risk). All jurisdictions will have one domestic RTGS (only one because there's only one central bank in each jurisdiction) and one (or more) domestic DNS. If you want real-time transfer, and you don't know the name of the RTGS system in your jurisdiction, then just ask your bank for RTGS, they'll know what you mean (and if they don't change your bank ASAP !). For international payments you've got SWIFT (and other options in the Eurozone). (For those not up to speed on banking acronyms, RTGS=Real-Time Gross Settlement, DNS=Deferred Net Settlement, i.e. they do what they say on the tin, one is "Real-Time", the other one is "Deferred")
I share this frustration with both the lack of urgency on wire's in general and the obscene fees they charge for something that costs them almost nothing. I'm not a huge fan, but I can tell you several wires out of my BoA accounts have hit within an hour of initiating in the morning, so they seem to be pretty quick. You pay for it though.
With RTGS there should be no "lack of urgency", it should be instant. If your bank is demonstrating "lack of urgency" with RTGS payments, CHANGE BANKS NOW !! With DNS, "lack of urgency" is to be expected. Your bank is not to be blamed. The "lack of urgency" stems from the underlying protocols defined by the DNS system. Time-sensitive payments should always use RTGS not DNS.
OP is too clever by ½. He should just leave enough money at his FCM to cover ordinary business ebbs and flows.
First I'm not sure any jackass wanting to wire $100K around is going to get access to RTGS with any retail bank? Do you know of any specific names that will? Also, in my experience it's not the wire system that is the problem. It indeed transfers money virtually instantaneously. It's the bank that gets around to processing your wire when they get around to it. That's the lack of urgency, and it's pretty pervasive in my experience.
First point, there is generally no significant lower limit on RTGS. If you're willing to pay the extra fee for RTGS then the bank will do it whether its $100,$1k,$100k or $1m. Secondly RTGS should be available to anyone at any bank if they're willing to pay the premium fee. Its a fundamental core part of the banking system, retail or otherwise, there are always going to be reasons for people to need access to a final and irrevocable payment method, which is something that only RTGS can offer.