Unless you are already rich and have capital to hand away to corporations to gamble what is the point. You're just giving away your money on the presumption there will be more in the long run and not paying tax on it now will somehow make you money later (IRA). Stock market is fool's game if you aren't in a position like the OP. The ONLY way to play would be very long term and even that money will ultimately not add up to much if you aren't re-investing heavily and adding from your income. Employer matching is the only reason I would ever contribute to an IRA.
Unless you already have your house, business, finances, family, etc., in order and cool 100 G's + put away (that you don't need) you should not be wasting your extra income on equities unless you have a great employer incentive and are able to get the money when you need it. What the OP doesn't reveal is in reality you already have to be extraordinarily wealthy to be able to make any real return that isn't over a very long time. I get the premise I finished my finance degree almost 3 yrs ago but let's be real here. What use is a 20% growth if it isn't realized.
Let's face the reality of this. The middle class is fucked. You will NOT become rich or wealthy as a middle class person with middle class income playing the stock market, in any way shape or form. OP probably makes much more than middle class figures and actually makes enough income to grow his portfolio consistently. Most people can't do that. This is what I would recommend for most that aren't in the finance world but want wealth.
What you youngsters need to do (I'm 26 which is like 60 on smogon) and this is of course following the premise of the thread, to one day 'retire' from working full-time and somehow live off of the money you're made, is accept that in order to retire one day you must become WEALTHY. Not rich, but wealthy, as in generational wealth. You must accept that the middle class and everyone in it is screwed, therefore you must escape the middle class.
-- Work your ass off. Make every meeting, appointment, follow up every phone call. You aren't doing shit with your time anyway, don't act like you need to schedule way future appointments with people. Don't get into shit debt like expensive cars or hurry into a mortgage.
-- Find ways to make MORE income. Instead of thinking 'oh if I just don't drink starbucks every day i'll save xx every year', think to yourself, how do I do more, how do I employ the 24 hours of my day instead of the 8-12 I spend at work. How do I add streams of income, how do I make more money from the same job I have now, how do I monetize all time of the day. Realize that your passion and your cash cow will rarely ever be the same thing and that is ok. You need to be in industries that pay well if you actually want to make serious money. It's not for everyone. Learn how to sell shit and you will never be without work for long. Also don't get into shit debt like expensive cars, credit cards, hurry into a mortgage, etc.
-- Invest your money into a business, or a vehicle that produces CASH FLOW. This is vital. If you're 20 something and only have 20k to your name, you better face the reality that you're barely above BROKE. If you are broke... Invest your time and energy into 1.) self improvement/growth/skill building, 2.) working and saving up cash like a squirrel saves nuts and eventually 3.) into a business or investment that's going to produce cash flow. As a young person you can afford to take much more risk.
-- Realize that we live in the 21st century. You cannot simply work and save your way into retirement like past generations could. We have the internet. Commerce flows 24 hours a day but we only 'work' to make money 8-12 hours. Think how you can use the internet and real businesses and cash producing assets that can work for you while you aren't working. I don't want to make 10-25% on something I have zero influence over (stock market), I want 200% and control/influence.
Once you have your first 100-500K depending on where you live you can leverage debt to take some risk and start your business or to invest in REAL assets and be in control of million $+ assets/businesses. You must never stop producing income but this is a way you will grow and develop real wealth that will secure your and your family's future. OP is of course qualified to be in stocks and I don't mean to discourage what he does. I respect OP and always enjoy learning from him but for most people I feel like they're just lazy and are hoping it doesn't all get washed out due to a crisis. The truth is you can be in control and you can weather extremely dire times by taking on the risk and control of your own income and not leaving your future to the mercy of massive banks.