*Any* published material is protected under copyright law, whether reproduced in whole or in part. Fundamentally, it is no less "wrong" to reproduce a choice few sentences than it is to cut and paste the entire article.
You are wrong, how much of the work you quote is relevant to determining whether the copying is allowed under fair use rules:
The law lists the following factors as the ones to be evaluated in determining whether a particular use of a copyrighted work is a permitted "fair use," rather than an infringement of the copyright:
• the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
• the nature of the copyrighted work;
• the amount and substantiality of the portion used in relation to the copyrighted work as a whole, and
• the effect of the use upon the potential market for or value of the copyrighted work.
Market Data 
Markets 
AI
