> Has anyone ever mentioned, or, do you know from your sources
> how many times a buy program will reset after a bottom has
> been reached during a trading day?
I'm not sure I exactly understand this question, but a 'buy program' is part of a tactic called statistical arbitrage; an index (available typically as a future, but sometimes as an option) price has diverged from the total of the underlying components of the index (for lots of reasons) -- since they theoretically have the same value, you can buy the cheap one and sell the expensive one, pocketing the difference. in the case of a 'buy' program, you're buying the stocks and selling the futures.
These kinds of programs are 'fire and forget' due to the nature of real-time markets (discussion of slippage elided) so they are one-shot and can be repeated if the arbitrage condition persists.
'Buy programs' typically do not result from low prices per se, but rather basket/index pricing instabilities (which can be exagerated due to high volatility that can accompany making lows for the day, but not necessarily).
> Or a signal given a trader on the floor from a
> computerized remote cue.
If you get a signal from a computer, automatic execution (bypassing the trader on the floor) is typically the result, since you can execute electronically much faster than you can via a human.
/jordan