I'm graduating engineering program in only six semesters but have gotten no serious work experience along the way. How much will grad schools care? I am a pet and Nat gas engineering student. I am graduating in six semesters (three yr) and this fall will be my fifth semester. I did not apply for an internship my freshmen year because I was under the impression no one hired freshmen. Therefore I assumed a rather standard summer job and figured I would certainly get one the next year. Now the oil and gas markets have completely crashed and there are almost zero internships right now. This was my last summer to find an internship before graduating and sending in graduate school applications. How much of a detriment will not having had any serious work experience be to my application? 

I began college right out of high school. I have a 3.5 gpa and though I have not taken the GRE yet, I imagine I will perform 95+ percentile judging from my SAT and looking at a few problems. 

I do not necessarily want to go to a top 20 graduate school for engineering, but I want to leave the door open because I am not quite sure what discipline I will be pursuing (but it will be some type of engineering or mathematical field). Do you think a six semester graduation in eng. (which judging from lack of online posts about it is almost unheard of) will be enough to be accepted into top 20 schools? 

One more question: I have both a stock and Foreign Exchange account which I do profit from. I write backtests and apply statistical analysis to determine what to buy. I do not usually list these "jobs" on resumes or applications because I'd find that pretentious, but do you think I should include it in my graduate school application since I am lacking serious work experience? 

EDIT: My question is not answered at all by the recommended question. I am seeking advice from ACADEMIA on this matter as I am not quite sure what to do. I am applying for a masters, not a PhD
The lack of professional or industrial experience will likely not significantly influence graduate admissions committees, particularly if you're planning to apply outside of your undergraduate field. However, what will matter is that you don't mention any real research experience that you've acquired in any field, whether your own or another. When applying outside your "home" area, this will almost certainly raise alarm bells for committees, because they will have little solid ground to decide whether you will succeed in their program or not. (For instance, they may have a hard time deciding if you can successfully complete the coursework phase of their program, and they may not be able to tell if you will be able to become a competent researcher in that program, if research is part of the degree.)