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by mjwhansen 3874 days ago
There are a lot of different schools of thought about approaching the stock market. One of them is the "chart" approach, where you (or an algorithm) try to discern the future movements of a company's stock price based on the past performance. Sometimes this works. Mostly, though, it doesn't.

There's also a big difference between "trading" and "investing." Trading is what you've described -- buying shares in the morning and hoping they'll go up in the afternoon so you can sell them later. Investing is buying shares of the company to become a part owner and hold them for years or decades, not days.

If you looked at NFLX's chart in 2012, you could "discern" that the share price would continue to hover around that price, maybe go up a little, maybe go down a little. And you could have bought it in September 2012 for $8 a share and sold for a nice $1 profit in October 2012 for $9 a share (split adjusted). But what the chart wouldn't have told you -- and would never have been able to tell you -- is that it would skyrocket in 2013 and up to its current split-adjusted price of $110 a share. The thing is, the chart never would have told you about this. And even a "pure" numerical analysis like could be done by a computer -- P/E ratios, cash flows, etc -- would not have predicted that growth. You could do DCFs all day every day in 2012 and never predict Netflix's rise. There are a lot of things that go into a company's rise that aren't numerical, like the quality of management, market moat, market growth, etc. And, of course, you had to buy it, and hold it for years, in order to see that return.

(In the interests of full disclosure, I should probably note that I'm a bit biased in this. I work for The Motley Fool, which advocates for long-term buy and hold investing, and produce a podcast for growth investors called Rule Breaker Investing.)

2 comments

Good point about trading versus investing. When index investing advocates say that it's hard to beat the market over the long term, I've always wondered what the difference is with traders. Do their returns beat the S&P500? Does an individual who trades forex as their day job do better than stuffing their money in an index fund for 40 years? Lately I've learned that larger traders can provide value apart from buy&hold, e.g. market making, finding the right price for something, shorting bubbles.
I don't have specific numbers on traders, but I do know that 80% of mutual funds underperform their benchmarks. One reason (of many) is that they're under pressure to provide numbers every quarter, or to seem like they're reacting when something short-term happens, so they sell out of positions that would have been more profitable had they held onto them.

Index funds are a great solution for investors who want to invest passively and get the market return (which averages 10% a year over the long term -- might be -20% and +30% year-over-year, though).

The thing with shorting bubbles is extremely difficult to get right, and "finding the right price" doesn't necessarily mean you're making a good decision. Amazon was trading around $300 a share earlier this year -- which many trader types saw as outrageous -- but it has doubled this year alone.

I suppose, in general, I follow the Black Swan approach: humans are terrible at predicting the future. Absolutely awful at it. But I'll take a "bet" on -- by which I mean, buy part of -- a company with great management/people and solid financials (i.e., no debt, positive revenue growth, FCF positive).

Computerized trading uses more than just historical price for input.