BreachExchange mailing list archives
Re: Data leaks hit share prices hard
From: "Allan Friedman" <allan_friedman () ksgphd harvard edu>
Date: Mon, 9 Oct 2006 17:54:58 -0400
The idea behind an event study is the critical "all other things equal" assumption. A security has some fixed value, a piece of news becomes known to the market, and the price adjusts based on how the news is percieved. At least in theory :) One upshot is that the "event window" or the period of time examined for an impact of the new information shouldn't span too much time, since many other things also affect a security's value. Happy to take a methodological discussion offline. In my experience, they are a fairly commonly used metric, but do not pass muster among the more serious of econometricians. allan On 10/9/06, DOpacki () covestic com <DOpacki () covestic com> wrote:
Indeed, but aren't we talking about means of assessing the performance of securities, not necessarily companies? Is it fair to conflate the two? After all, the link you sent indicates that "the way that markets react to news surprises is perhaps the most visible flaw in the efficient market hypothesis". What are data breach disclosures, if not news surprises? -Dennis ________________________________ From: Chris Walsh Sent: Mon 10/9/2006 11:50 AM To: Dennis Opacki Cc: Allan Friedman; dataloss () attrition org Subject: Re: [Dataloss] Data leaks hit share prices hard The underlying theory is generated via the so-called efficient markets hypothesis, which holds that stock prices reflect all information available to the market about firms' expected future returns. http://en.wikipedia.org/wiki/Efficient_market_hypothesis This is a contentious issue :^)
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Current thread:
- Data leaks hit share prices hard Dissent (Oct 09)
- Re: Data leaks hit share prices hard Adam Shostack (Oct 09)
- Re: Data leaks hit share prices hard B.K. DeLong (Oct 09)
- Re: Data leaks hit share prices hard Allan Friedman (Oct 09)
- Re: Data leaks hit share prices hard Chris Walsh (Oct 09)
- Re: Data leaks hit share prices hard Dennis Opacki (Oct 09)
- Re: Data leaks hit share prices hard Chris Walsh (Oct 09)
- Re: Data leaks hit share prices hard Dennis Opacki (Oct 09)
- Re: Data leaks hit share prices hard Allan Friedman (Oct 09)
- Dataloss discussion, debate and chatter security curmudgeon (Oct 09)
- Re: Data leaks hit share prices hard Adam Shostack (Oct 09)
- Re: Data leaks hit share prices hard B.K. DeLong (Oct 09)
- Re: Data leaks hit share prices hard Adam Shostack (Oct 09)
- Re: Data leaks hit share prices hard Alessandro Acquisti (Oct 10)
- Re: Data leaks hit share prices hard ziplock (Oct 10)