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Re:Bitcoin falls from $266 by brazzy on Wednesday April 10, 2013 @05:52PM (#5528456)
Divining that a price that is rising in a superexponential manner will be going down sometime soon is one of the least fooling things one can do when looking at a graph.
Re:Bitcoin falls from $266 by InclinedPlane on Wednesday April 10, 2013 @10:45PM (#5529662)
Define "soon". Anyone could have looked at the stock market in 1998 and said that it was sure to be going down soon but it took a few years for that to be the case. And anyone could have looked at the housing market even in 2003 and been waiting for it to go down "sometime soon", and been waiting half a decade for it.

Keynes may have been mistaken on a lot of things but he got one thing right: "The market can stay irrational longer than you can stay solvent."

Re:Bitcoin falls from $266 by brazzy on Thursday April 11, 2013 @04:18AM (#5530643)
> Define "soon"

My specific prediction less than a day before this crash was "At this rate, the crash is a single-digit number of days away".

The market can NOT stay irrational for long when an asset's price doubles every few days.

https://news.ycombinator.com/item?id=5517460

Re:Bitcoin falls from $266 by Evbn on Thursday April 11, 2013 @10:42PM (#5536274)
What was Keynes wrong about? (Keynes, not Keynsians)
Re:Bitcoin falls from $266 by saraid216 on Wednesday April 10, 2013 @07:08PM (#5528820)
Are we really having a serious conversation on divination on HN?
Re:Bitcoin falls from $266 by verbalist on Wednesday April 10, 2013 @10:41PM (#5529651)
It's the ultimate hack.
Re:Bitcoin falls from $266 by bdr on Wednesday April 10, 2013 @06:49PM (#5528749)
You are empirically wrong. Please, quantify your idea and go backtest it on the stock market.

The efficient-market hypothesis does not have an asterisk excluding cryptocurrencies.

Re:Bitcoin falls from $266 by lotyrin on Wednesday April 10, 2013 @07:34PM (#5528951)
So... going up super-exponentially is efficient-market, but a crash is an attack? Is that what I'm hearing?

Truly, the capacity for people to employ cognitive bias is staggering.

Re:Bitcoin falls from $266 by brazzy on Thursday April 11, 2013 @04:23AM (#5530659)
Quantification: "An asset whose price has doubled several times, with the time between doublings growing shorter and having reached less than a week, will see an abrupt correction to less than 50% of the peak value within 10 days.

I think you'll find that I'm empirically right.

Re:Bitcoin falls from $266 by phyalow on Wednesday April 10, 2013 @07:09PM (#5528827)
the efficient market is dead and always has been.
Re:Bitcoin falls from $266 by derleth on Wednesday April 10, 2013 @07:35PM (#5528955)
> the efficient market is dead and always has been.

This is what people mean when they say "efficient market" in this context:

> In finance, the efficient-market hypothesis (EMH) asserts that financial markets are "informationally efficient". In consequence of this, one cannot consistently achieve returns in excess of average market returns on a risk-adjusted basis, given the information available at the time the investment is made.

http://en.wikipedia.org/wiki/Efficient-market_hypothesis

There are variations of this hypothesis, so saying "it's dead" is meaningless unless you specify which one is "dead" and how it has failed.

Re:Bitcoin falls from $266 by Retric on Wednesday April 10, 2013 @08:35PM (#5529160)
There are generally arbitration opertunity's that offer short term rewards well beyond the standard risk reward curve. Which is how many algorithmic traders consistently return high double digit returns with ought leverage. The simplest being having a mix of buy and sell orders that straddle the average.
Re:Bitcoin falls from $266 by tatsuke95 on Thursday April 11, 2013 @10:48AM (#5532264)
Which is exactly what the hypothesis says. Assume that others are using arbitrage to reduce your opportunities, leaving you with an efficient market.
Re:Bitcoin falls from $266 by Retric on Thursday April 11, 2013 @11:09AM (#5532411)
Except arbitration requires more than just money + information, people doing arbitration must have low fees / latency for example so it's not available to all players in the market. Net result real world markets are not efficient due to various access levels.

Also: Empirical analyses have consistently found problems with the efficient-market hypothesis, the most consistent being that stocks with low price to earnings (and similarly, low price to cash-flow or book value) outperform other stocks. Which is presumably due to cognitive bias. http://en.wikipedia.org/wiki/Efficient-market_hypothesis

PS: It's a reasonable simplification that's useful for the average investor, but not policy makers for example.