3 ms·

This is bad analysis. It's not even close to absolute. He's not accounting for the volatility of the stock. That's the reason that premiums on tsla options ha

This is bad analysis. It's not even close to absolute. He's not accounting for the volatility of the stock. That's the reason that premiums on tsla options have been and are so incredibly high. He didn't even mention that the SPY is much less volatile over its entire history than TSLA individual stock considering it's an index of 500 large/mid cap stocks. Of course it's going to be less volatile. Did he tank it? Maybe, but every tech stock had a dip around 11am. If he tanked it then the sentiment analysis bots tracking his tweets need to be tweaked a bit.

flyGuyOnTheSly 6y ago
AMZN's dip [0] looks nothing like TSLA's [1] today though. Founders commenting on the valuation of their company is absolutely tradeable news to day traders. I would argue that this tweet directly affected TSLA tanking in price immediately after it landed. [0] https://www.google.com/search?client=firefox-b-e&q=amazon+stock+price https://www.google.com/search?client=firefox-b-e&q=amazon+st... [1] https://www.google.com/search?client=firefox-b-e&q=tesla+stock+price https://www.google.com/search?client=firefox-b-e&q=tesla+sto...
- AznHisoka 6y ago
  AMZN is an outlier today because they reported earnings last night. Better to compare it to an index.
  - jimmySixDOF 6y ago
    ... and also skewed by the WSJ article on unfair third-party seller treatment that contradicts previous house Judicial Committee testimony and may lead to new hearings... The problem with muddy water is it's muddy.
  - flyGuyOnTheSly 6y ago
    The DOW looks almost identical to AMZN.
cuchoi 6y ago
I agree. Synthetic controls can be powerful but they are not magic wand for causal analysis. The fit on the left seems too good to be true. It could be that it using the outcome (Tesla's stock price) as part of the calibration, which biases your synthetic control. In ML speak it is an overfitted model. http://www.oekonometrie.uni-saarland.de/papers/SCM_Predictors.pdf http://www.oekonometrie.uni-saarland.de/papers/SCM_Predictor.... Also, in the package documention it says "The model also assumes that the relationship between covariates and treated time series, as established during the pre-period, remains stable throughout the post-period". In this case the covariate is the S&P500, so clearly the relationship didn't stay stable. As you mention, there was a dip in every tech company. This doesn't mean that Musk's tweet didn't affect the price, but this is no proof.

flyGuyOnTheSly 6y ago

AMZN's dip [0] looks nothing like TSLA's [1] today though. Founders commenting on the valuation of their company is absolutely tradeable news to day traders. I would argue that this tweet directly affected TSLA tanking in price immediately after it landed. [0] https://www.google.com/search?client=firefox-b-e&q=amazon+stock+price https://www.google.com/search?client=firefox-b-e&q=amazon+st... [1] https://www.google.com/search?client=firefox-b-e&q=tesla+stock+price https://www.google.com/search?client=firefox-b-e&q=tesla+sto...

AznHisoka 6y ago
AMZN is an outlier today because they reported earnings last night. Better to compare it to an index.
- jimmySixDOF 6y ago
  ... and also skewed by the WSJ article on unfair third-party seller treatment that contradicts previous house Judicial Committee testimony and may lead to new hearings... The problem with muddy water is it's muddy.
- flyGuyOnTheSly 6y ago
  The DOW looks almost identical to AMZN.

cuchoi 6y ago

I agree. Synthetic controls can be powerful but they are not magic wand for causal analysis. The fit on the left seems too good to be true. It could be that it using the outcome (Tesla's stock price) as part of the calibration, which biases your synthetic control. In ML speak it is an overfitted model. http://www.oekonometrie.uni-saarland.de/papers/SCM_Predictors.pdf http://www.oekonometrie.uni-saarland.de/papers/SCM_Predictor.... Also, in the package documention it says "The model also assumes that the relationship between covariates and treated time series, as established during the pre-period, remains stable throughout the post-period". In this case the covariate is the S&P500, so clearly the relationship didn't stay stable. As you mention, there was a dip in every tech company. This doesn't mean that Musk's tweet didn't affect the price, but this is no proof.