When not editing people’s manuscripts, one of my interests/occupations is investing. In thirty years, I’ve paid lots of investing tuition, which means I made stupid mistakes that cost me money. This has taught me some things, ones I can distill into the modern attention span, so here they are.

• Stock and index raw numbers do not matter. Only percentage change matters. If you see a headline like DOW JUMPS 100, and you care, you are incorrect.
• The Dow sucks (and not just because it’s the market’s FUD dispenser). When it’s done, it sucks some more.
• The money media spend long hours trying to scare you into reading their media. None ever get fired for being wrong. So we keep reading them…why?
• All fees and taxes matter. Never ignore any fee or tax; that’s the path to self-delusion.
• Any investment setup that looks like a cutesy little dance, such as little gimmicky stuff that gives you free money to invest, is probably an e-monte game designed to tap into your “omg i could get rich yes plz” wishes. Read the terms, especially those about how you get out when you want to. Bears repeating: Watch the fees. Yes, even those little ones. Yes, those too. And yes, that one. Do you sense a trend? Are they targeting those at younger and less experienced investors? Well, what do you think? Do you suppose that it’s aimed at people who know much about what they are doing? If it’s that great, wouldn’t affluent older people be doing it?
• Wall Street gets to cheat; you don’t. Love that or hate it, but it is what you will live with, and no one with the power to change it will ever do so.
• Anyone who uses the word “bagger,” without “grocery” or “vance,” start ignoring. Just put an R after the B and all will be clear.
• When you are young, time is your friend. Most young people will reject this friendship. I get it; so did I. I was a young idiot. If it were easier to accept that friendship, more young people would do it.
• Even your brokerage will give Big Money better deals than it will to you. They will only be surprised if you act surprised (or outraged) by it, as if all people were created equal or something. In investing, you would be a hopeless naïf to believe this, and they would treat you with the gentle restraint and pity typically shown toward volatile persons missing a few marbles.
• The three main ways to make money investing are to: sell it for a profit, get it to pay you, and/or save on your taxes. Growth, income, tax advantages. That’s them.
• You really can’t know how you’ll react to big gains and big losses until you experience them. What you say about them now is irrelevant. What you do when the crowd’s going wild, or the building is on fire, is your investing identity.
• Most non-index mutual funds do not beat their target indices, raising the question of why pay them more in order to do worse.
• Conventional open-end mutual funds have some inherent flaws that harm performance.
• Understand every investment you buy. It is very stupid to buy something and then go find out what you just got.
• The biggest enemy of your success is your own emotions, both greed and fear.
• If you just read the above and though, “Aha! I’m a man, and the women are more emotional, so I have the advantage!”, your furry ass is showing. A book called Warren Buffett Invests Like a Girl makes a convincing case that women are likely to be better investors, more prone to do their research homework. I wouldn’t take any generalization too far, but read that book before you start patting your XY chromosomes on the back.
• If that doesn’t convince you, consider this. With the exception of Berkshire, the only separate issue stocks that have ever succeeded for me were the ones my wife picked. She knows very little about investing. She rarely misses. I don’t even buy them any more, except those she directs me to buy. If you want to know her secret, it’s not very complicated; she buys stock of companies she likes and uses.
• If you want to punish an evil company, don’t boycott their stock.  That’s mindless, and doesn’t hurt them. Want to mess them up? Buy a bunch, and then vote against management every time in shareholder elections, especially for the loopy proposals management recommends you vote down. Donate the dividends to anti-company causes if you like. But don’t confuse activism with investing, because they do not have the same goals.
• If your job has a 401k, and you aren’t putting in at least up to the employer’s match, you are financially self-harming. They’re offering you free money and you are refusing it.
• As you change jobs, roll your old 401ks into a rollover IRA, then manage them yourself. You will have better and more options.
• Read good books about investing. Ask successful investors which are good books, and why. Don’t read stupid books.
• If you’re tempted by an investment newsletter, start by rejecting any that arrive as junk mail.
• If you just want the market return and can be happy with it, buy and hold index ETFs. If you did that consistently, you’d probably end up with a pile without having to do any work.
• Every minute you spend watching Jim Cramer, you’ll get a little dumber. About 160 hours might be a functional financial lobotomy.
• “It’s different this time” are investing’s famous last words.

It’s up to you. Good hunting.