Thursday, April 20, 2017

Yeah, I Got Your Efficient Market Hypothesis Right Here: O'Reilly Auto Parts Edition (ORLY)

Now class, recite along with me:
(sorry Professor Fama) 
At any given time and in a liquid market, security prices fully reflect all available information.
From Price Action Lab:

Dumb Social Media Sentiment Algos Target The Stock of O’Reilly Automotive
Increased volatility in the stock of O’Reilly Automotive (ORLY) in the last two days while the name O’Reilly was trending in the news raises questions about the effectiveness of social media sentiment algos and their perils.

There is a small probability that the two events are unrelated and the stock of O’Reilly Automotive (ORLY) rallied in the past two days because of normal market activity but this happening while the name O’Reilly was trending in Twitter and social media raises some questions about what is really happening in Wall Street. What are the risks from dumb algos taking over Wall Street?...