They have been doing that on the Yahoo boards. Get yourself together... Or just keep following Bobby. By the way what is your definition of statistically significant increment of time? 10000 years? You know what? I will wait for someone who has a statistically meaningful number of posts to discuss this.

Oh my. You're a charmer. A little prickly, too. You must not be terribly sure of yourself. Your tenor is pretty classic: stentorian True Believer. I question you, and you fall back onto an argument of ... seniority? Really? Because I guarantee you you'd lose that contest IRL. Not that this is a contest. It's a friendly debate. Right? You remember how to be friendly, don't you? And how to debate? Bueller? Bueller?

Except your profile says you're a girl. (Caitlyn?) And for someone who "has insight into Jim Simon's quant shop" and considers retail trading success as "noise," it's surprising you can't even spell Ray Dalio's last name correctly in a previous post: http://www.elitetrader.com/et/threads/what-is-fueling-the-s-ps-growth.301408/#post-4307512 Having said that, I agree with your point about Karen and how the big boys would follow her strategies if they were so profitable. But it's too bad ET has so many questionable posters and posers.

I thought sigma was the relationship to defects in manufacturing. As in 6 sigma. What is 12 sigma and 20 sigma and how does it relate to options and stock trading?

Yes its similar. Sigma is short for standard deviation. Six Sigma relates to the percentage of defect-free products a manufacturing process creates. A six sigma process is one in which 99.99966% of all opportunities to produce some feature of a part are statistically expected to be free of defects (3.4 defective features per million opportunities). Source: https://en.wikipedia.org/wiki/Six_Sigma In finance, standard deviation is often used as a measure of the risk associated with price-fluctuations of a given asset (stocks, bonds, property, etc.), or the risk of a portfolio of assets (actively managed mutual funds, index mutual funds, or ETFs). Standard deviation provides a quantified estimate of the uncertainty of future returns. Calculating the average (or arithmetic mean) of the return of a security over a given period will generate the expected return of the asset. For each period, subtracting the expected return from the actual return results in the difference from the mean. Squaring the difference in each period and taking the average gives the overall variance of the return of the asset. The larger the variance, the greater risk the security carries. Finding the square root of this variance will give the standard deviation of the investment tool in question. https://en.wikipedia.org/wiki/Standard_deviation So a 20 sigma move is a move of 20 standard deviations or a move that mathematically would be incredibly unlikely (2.75 * 10^-89 as stated in the paper) if the market returns were normally distributed. Which turned up not to be the case as these moves happen a lot more often. HTH

Wow thank you so much for this tip!!! The Wall Street Warriors "lost season" that has finally surfaced! I so much love to watch this: Slick guys in suits talking money, sunglasses, houses in the Hamptons. This is so ridicoulous. And now Tom and Tony inbetween! This is so much fun. Lets see how it continues ...in autumn 2008 .

I think that paper references the 20 sigma, anyway when you start talking 3-5% moves in the indexes you are gonna get hurt. You could look at options on GBP/USD and compare before during and after. Hope you came out okay on your position.

This is precisely why Karen strategy will blowup eventually (and so do others such as LTCM). The black swam is actually just a "grey" swam in finance world and happen quite frequently..

One trade today. I sold the SPY 16 SEP 16 205P(1) with 53 DTE. Theta is 229, delta is -776, vega is -1070. My experiment is treading water and is up $2,506 since inception on April 5. Bobby

Here's what I know: You have 2K+ posts and a single "like". It's not hard to see why. With brittle, cranky pedants such as yourself spreading harmony and understanding, it's not hard to see why I'll be spending less time here. I hereby apologize for misspelling Ray Dalio's last name. Cognitively, I used the handle of "dahlia", and my mnemonic spilled over. You do know what a mnemonic is, don't you? Poser? I run a family office with around $50M aum. Started much, much smaller. Silicon Valley programmer from the '90s, shifted to working on Wall Street building black boxes. Built a bunch of proprietary stuff with everything from C to Matlab to proprietary ANNs. Once upon a time, wrote extensively for the national press, which is why profile obfuscation. Of course, all invalidated because I misspelled Dalio. I think I know who the poser is.