<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>teawrecks</author><text>Making an assumption about the population based on a small non-random sample is usually the belief that needs to be justified by evidence.</text><parent_chain><item><author>georgespencer</author><text>Wouldn&amp;#x27;t you need a basis for believing that day trading Brazilian futures has unique properties not present in other markets to assert this? E.g. the volatility or spread is significantly larger than European futures or the information flow is more tightly de&amp;#x2F;regulated etc.&lt;p&gt;Is there a basis for believing this?</text></item><item><author>DSingularity</author><text>Because that is not a representative sampling of the day trader population. Assuming the techniques of the study were sound, at best we can conclude whether or not day trading Brazilian futures is a sustainably profitable undertaking.</text></item><item><author>soneca</author><text>Why weird?</text></item><item><author>davidu</author><text>I don&amp;#x27;t doubt the headline, but &amp;quot;We observe all individuals who began to day trade between 2013 and 2015 in the Brazilian equity futures market&amp;quot; seems like a weird way to come to that conclusion.</text></item></parent_chain></comment><story><title>Day Trading for a Living?</title><url>https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3423101</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>C1sc0cat</author><text>Kind of not all exchanges are equal, professional investors still don&amp;#x27;t trust the main Chinese exchange.</text><parent_chain><item><author>georgespencer</author><text>Wouldn&amp;#x27;t you need a basis for believing that day trading Brazilian futures has unique properties not present in other markets to assert this? E.g. the volatility or spread is significantly larger than European futures or the information flow is more tightly de&amp;#x2F;regulated etc.&lt;p&gt;Is there a basis for believing this?</text></item><item><author>DSingularity</author><text>Because that is not a representative sampling of the day trader population. Assuming the techniques of the study were sound, at best we can conclude whether or not day trading Brazilian futures is a sustainably profitable undertaking.</text></item><item><author>soneca</author><text>Why weird?</text></item><item><author>davidu</author><text>I don&amp;#x27;t doubt the headline, but &amp;quot;We observe all individuals who began to day trade between 2013 and 2015 in the Brazilian equity futures market&amp;quot; seems like a weird way to come to that conclusion.</text></item></parent_chain></comment><story><title>Day Trading for a Living?</title><url>https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3423101</url></story>