I guess it prevents people hammering the servers to get the earning reports ASAP.

With this, people have a few hours to get the reports which means miliseconds matter less.

...which happens anyway. Starting 5-10 minutes before the official earnings reports come out, investor.google.com gets hammered by bots, requesting every few milliseconds until the actual page is released.

I knew an SRE that wanted to put up a fake earnings report until the official time at which the real one was released, to disincentivize this behavior, but the lawyers nixed that idea really quick.

Why didn't they just decide to delay the posting by 30 seconds? It's not like that would deter regular users but it completely eliminates the high speed trading case.

Uncertain - I'm not exactly the decision-maker. But I can think of two reasons:

1) They say that earnings will come out at a certain time, so they better be out at that time or else the SEC comes after them. If they just posted earnings as coming out at say 12:00:30 instead of 12:00:00, that just shifts the problem 30 seconds later.

2) The bots will just run for an extra 30 seconds, and will still have the advantage over ordinary people.

(Something I'm not clear on: regular Google - and Hacker News, for that matter - will sometimes just make a user's connection slower if they repeatedly hit it with traffic. Why not use that on bots that hammer the investor relations site? It completely disincentivizes these bots if the 100 requests you made at 11:58:30 mean that you get stuck with a 5 minute delay and don't get the information until 12:03:30. Or maybe they do use this approach and the SRE in question just didn't bother to tell me.)

Oh, I’m sorry. I thought you were referring to the finance information on finance.google.com, not investor information about google itself.

For the latter, companies are not required to release reports on their website in a timely manner. That’s what EDGAR is for.

Accessors who really care would just hit it from multiple IP's? And keep adding distributed IP's until they got what they wanted.

There's nothing you can do to eliminate the high speed trading case short of outlawing automated trading. As long as computers can trade, they'll compete on speed and nothing you do can prevent that. You could forcibly slow down trades to 1 a minute, and you'll still have bots competing on speed to be the first trade each minute and they'll still beat humans.

In 2012 Google's 8K earnings filing was accidentally released 3 hours early. https://www.businessinsider.com/google-blames-rr-donnelley-f... Their stocked tanked 10% before trading was halted

But it was an earnings filing in which they did not meet expectations - this strongly suggests that the stock would have tanked anyway, regardless of timing.

One can earn money on options that expire before the publication. If the market has not expected any surprises, such options can be rather cheap.

Because they need time to correct errors and to prevent fraud. Say someone gets into the SEC and decides to release a fraudulent report. If that happens during off hours it can be rectified, but if it happens during the trading day the markets will react instantly and the damage is done.

Fixed release times also means that the companies submitting the filings cannot pick an advantageous time. Imagine if Musk was sitting atop a really horrible Tesla earnings report. If he could manipulate the exact time of its release he could leverage all sorts of things.

>but if it happens during the trading day the markets will react instantly and the damage is done.

Sounds like a good hacker movie.

>If he could manipulate the exact time of its release he could leverage all sorts of things.

There's already protection against him insider trading. Not sure what else "leverage all sorts of things" is.

Market trade panics are positive feedback loops. The closure of the market and the release of data while the market's closed allows investors to digest new information and move with their heads, not their hearts, decreasing the risk of regrettable shocks.

Meh, stocks trade after hours immediately after release so this excuse leaves something to be desired. It also doesn't account for the before open releases.

> Why is it better for that moment to be at 9:30 instead of say noon?

Because the market opens with an auction, giving everyone time to retrieve the information, digest it, and place their orders. Whereas, if the market is already open, whoever's closest to the source of information, and the exchange, has an advantage.