3 ms·

Your explanation does not disprove the EMH as far as I can tell. Sure, there's some people who will have information sooner than others. In fact, the EMH says

Your explanation does not disprove the EMH as far as I can tell. Sure, there's some people who will have information sooner than others. In fact, the EMH says that "people who outperform the market do so based on chance" and it's expected that some people do win some of the time. What better test of chance than who guesses the password soonest by luck? Okay, fine, it's not luck you say, it's whoever has the best supercomputer to crack the password each time that happens. However, in reality, contrived examples like brute-forcing passwords aren't frequent parts of the stock market. Rather, it's events that traders predict the potential impact of, which is much closer to a random affair. What you've shown in your comment is that it's difficult to clearly define private and public information in some contrived cases.

viraghrr 8y ago
I think difficult analysis is a very frequent part of the stock market. My argument was not so much about luck as about speed of analysis. EMH doesn't allow some people to analyze information faster than others. For example if Intel always releases a 450 page earnings at 11 o'clock, and it takes 4 hours for the market to really analyze it because it's written really abstrusely and that's the fastest anyone can read and figure out its meaning, then under the EMH there's no scope for 1 specific trader to read it in 1 hour and perform the analysis faster, before the price has adjusted to the new information. In fact, under the EMH the price has to instantly fully reflect the implication of the information of the report the moment it is released. If two hours in, a famous analyst (Warren Buffett let's say) tweets about it, and that tweet moves the price, under the EMH it must have moved the price because of new information. It can't just be because the famous analyst is smarter and analyzes better and faster than the rest of the market. Not possible. That doesn't mean that until the tweet the analyst's better-than-market analysis is somehow "private" (rather than public) for 4 hours. there's no new information, it's just that the public price doesn't fully reflect the completed analysis. The market can be a bit dumb. But how do you know the facts I just gave are true? How do you know the completed analysis can't be factored into the price the instant the report is released? (The price does jump instantly.) Maybe it jumps to the new fully completed analysis price? Maybe everything I wrote is not true and in fact the market is perfectly efficient, and only new information, or stochastic events, change the price? Maybe it fully reflects all public information all the time? So I showed how to show that analysts can't all work instantly, yes, under a contrived example. The EMH doesn't require that markets only be efficient under conditions that aren't "contrived". But rather, all the time. you can run the experiment and show it if you want. you can literally see the stock market figure it out. They could also figure it our wrong. Maybe early on #117 will spike (so that prices look like this: https://imgur.com/a/C782Fgt https://imgur.com/a/C782Fgt ) - it could be for any reason. Maybe a false rumor that it was leaked (a false leak), whatever. But the market gives the rumor just a 10% chance of being true. But regardless of the reason for the spikes, at the end there must be a single spike, in the value of the stock that actually wins. it must be around $1 billion since it'll have that in cash. (It's important that people actually believe this will happen.)

viraghrr 8y ago

I think difficult analysis is a very frequent part of the stock market. My argument was not so much about luck as about speed of analysis. EMH doesn't allow some people to analyze information faster than others. For example if Intel always releases a 450 page earnings at 11 o'clock, and it takes 4 hours for the market to really analyze it because it's written really abstrusely and that's the fastest anyone can read and figure out its meaning, then under the EMH there's no scope for 1 specific trader to read it in 1 hour and perform the analysis faster, before the price has adjusted to the new information. In fact, under the EMH the price has to instantly fully reflect the implication of the information of the report the moment it is released. If two hours in, a famous analyst (Warren Buffett let's say) tweets about it, and that tweet moves the price, under the EMH it must have moved the price because of new information. It can't just be because the famous analyst is smarter and analyzes better and faster than the rest of the market. Not possible. That doesn't mean that until the tweet the analyst's better-than-market analysis is somehow "private" (rather than public) for 4 hours. there's no new information, it's just that the public price doesn't fully reflect the completed analysis. The market can be a bit dumb. But how do you know the facts I just gave are true? How do you know the completed analysis can't be factored into the price the instant the report is released? (The price does jump instantly.) Maybe it jumps to the new fully completed analysis price? Maybe everything I wrote is not true and in fact the market is perfectly efficient, and only new information, or stochastic events, change the price? Maybe it fully reflects all public information all the time? So I showed how to show that analysts can't all work instantly, yes, under a contrived example. The EMH doesn't require that markets only be efficient under conditions that aren't "contrived". But rather, all the time. you can run the experiment and show it if you want. you can literally see the stock market figure it out. They could also figure it our wrong. Maybe early on #117 will spike (so that prices look like this: https://imgur.com/a/C782Fgt https://imgur.com/a/C782Fgt ) - it could be for any reason. Maybe a false rumor that it was leaked (a false leak), whatever. But the market gives the rumor just a 10% chance of being true. But regardless of the reason for the spikes, at the end there must be a single spike, in the value of the stock that actually wins. it must be around $1 billion since it'll have that in cash. (It's important that people actually believe this will happen.)