So your argument is...what?

Hypothetically: Let's say I have an inventory of stock A, which I think is worth X, and which try and sell whenever the market price climbs above X. Now there's some new public knowledge that materially impacts my estimation of the value of that stock (eg, a large hedge fund has started buying large blocks of this stock): I no longer think it's worth X, but actually Y, and I'd like to stop selling it whenever the price climbs above X, and instead wait until the price climbs above Y.

So you're saying that's okay, and I can price my inventory however I want, but only if I give the hedge fund a chance to buy a bunch of underpriced stock first? This raises some questions such as:

1) Why on earth is that a good rule?

2) How much time do I need to give the hedge fund? Do they only need a few seconds? Should they get a day? A week? At what point am I allowed to change the price I'm selling stock A for without it "interrupting" the hedge fund? Do they need to announce that they're done, or is their a timeout period after which I can just assume? Can I change the price I charge other people if I still let the hedge fund buy at the old price, or does everyone get the discount?

3) Or is it not about time, but about amount? Does the hedge fund have some divine right to buy as much stock as they want without it driving the price up? Why? And how come nobody else has that right? Do you have to be a hedge fund to get the right to name your own price, or do normal people get to do that too?

4) Or is it somehow okay if I'm selling, but not buying? Is it's okay for me to raise the price I'm willing to sell stock A for if I find out a hedge fund is investing, but not okay for me to raise the price I'm willing to buy stock A for? What happens if I find out a hedge fund is liquidating their position instead? Do I get to lower the price I'm willing to buy and sell it for, or just one of them? There's no laws or SEC regs about this; is there a list of rules somewhere? Is it in the bible?

5) Does this only count market actions? If the hedge fund gives a Bill Ackman style press release about how some company is terrible and should be prosecuted, can I change my prices immediately, or do I need to wait in case I'm interrupting some hedge fund strategy? I mean, maybe they were planning on giving the press conference and then buying a bunch of stock; if I think their arguments are bollocks and I buy a bunch first, is that interrupting them?

And so on. The entire argument seem awfully focused on why large hedge funds and investment banks should be able to ignore basic market rules. I'm sure they'd like to; I'm still waiting to hear why they should. (One of my favourite scenes for Lewis's Flash Boys was when a trader expresses outrage that his very large order in a thinly traded stock caused the price to move against him. How terrible; if only there was a law that required people to trade with him at the price he chose...)