Where are you getting bottom quintile? If you don't have $1000 for an emergency, it doesn't matter what quintile you're in you're still not going to be maximizing the profitability of your excess capital using the stock market

If you are not poor and yet choose to spend all your money, yes you can have nothing left to invest. If this is happening to you, you might consider counseling from a financial advisor.

Ok so let’s slice it up. 25% of the pop is, in your view, legitimately poor... lowest quintile. Which leaves 61-25 = 36% of the population of the US is just bad at money and it’s their own fault?

I would be very hesitant to make an uncharitable assumption about that many millions of people - their situations are likely more complex than you or I understand.

Best case scenario, you are right, and we are failing massive swaths of the population by not teaching good money management as part of the core education everybody receives. Either way, things are broken right now!

A quintile would be 20%, not 25%.

I've advocated many times on HN that public schools teach basic accounting and how a free market economy works.