Hi tamrik92. Welcome!
Is this a rhetorical question out of frustration, because we'd all like faster transactions. The question is, what is practical, and what is possible?
The way I understand it, and someone can please correct me if I'm wrong This may be a little disjointed...
The TSP processes all daily transactions by the close of business to report these transaction to the stock market (for lack of a better way of describing it) and they report this by posting the share prices by just after 7 PM ET. These transactions have to be input by us to the TSP, not the stock market - before noon ET to be part of that day's close of business processing. I assume this is for both convenience on their part, and maybe to discourage us from "trading."
I think 8:30 - 9:00 AM transactions wouldn't be practical for the TSP to process (buy and sell because they would somehow have to get this information for your particular account to the "stock market" and it would probably have to be done on an individual account basis.
So, at 8:45 AM you decide to move your money to the S-fund. You are telling the TSP this when you enter your IFT. At the end of the day the TSP gathers all of those transactions of re-balancing the allocations, then send that as one big order to the "stock market"
I don't think there is an easy way for the TSP to tell the stock market each individual's transactions, but rather the one big transaction at the end of the day based on the day's activity of all of the TSP participants.
The question is, and the change that could be more practical now with speed of transactions, is why can't they make our IFT deadline closer to the end of day? The bond market closes an hour before the stock market so I think 2:00 - 2:30 PM would be a reasonable request instead of noon.
I hope that helps.