‘Efficient market’ is one of the most important terms to understand when it comes to investing. It’s important because what you think about the efficiency of the market will dictate how you practically invest your money, which will shape your retirement and legacy.
So first, what does it mean? If the market is efficient it means that stock prices react to news and information really fast. For instance, news breaks that a company has committed fraud, and the stock price of that company falls immediately. It also extends to any small bit of news or public sentiment regarding the market or specific companies. Market prices are always moving based on new information and perceptions, and they move almost immediately upon receiving that new information. Those are signs of an efficient market. The speed at which information travels today has only made the market more efficient.
So why does that matter? Well, if the market really is super efficient, it means that picking stocks is futile. Think about it, if the market prices react and update immediately upon receiving new information, the only thing you can do to beat the market is to guess right. Unfortunately market guesses are less like investing and more like gambling. So if the market is efficient, the entire way you’ve previously thought about investing is not only impractical, it’s basically a roll of the dice. Instead of trying to beat the market, an efficient market would suggest you own the whole thing as efficiently as you can. You would diversify and hold stocks instead of research and pick stocks.
There is another important thing to recognize about investing in relation to the efficient market: people do beat the market sometimes, they sometimes pick the right stocks and get better returns than the market as a whole. It’s not often, somewhere around 90% of stock pickers underperform the market every year, but that leaves around 10% who seem to be doing something right. That 10% either figured something out, found some inefficiency in the market, or they got lucky. The thing is, it doesn’t really matter if they’re smart or lucky, and there’s not really any way to empirically test it anyways. Because the market is efficient, if a smart person does find an inefficiency it will close up before long, and if a lucky person gets lucky, they’ll also get unlucky at some point. Either way, by the time you’ve heard about their success, it’s too late. People who have beat the market in the past are much more likely to underperform the market in the future than to beat it again. In fact, they’re more likely to underperform even their contemporaries in the future. Any way you cut it, in an efficient market it simply doesn’t make sense to try to find or profit from market inefficiencies, regardless of whether or not they really exist, or to what extent.
So if the market is efficient, to whatever degree you agree, don’t try to beat it. Instead, own the efficient market as efficiently as possible.
Gambling
Robinhood is dangerous
First of all, I don’t mean Robinhood the vigilante, the hero. Sure, was a criminal, but at least he was fighting against the bad guys. In an unjust agrarian society, his actions could be seen as defensible, but I digress.
I mean Robinhood the investment app. A few notes on its danger:
- The Robinhood app is gorgeous. It’s so pretty it’s hard not to look at it. The graphs and charts are perfect, the animations and gestures are seamless, the design is minimal, it’s about as well designed as apps come. The old mantra ‘beauty is only skin deep’ applies here. The beauty draws you in but also masks some sordid parts.
The beauty of Robinhood masks the fact that it’s essentially a place to gamble. Sure, you could call it sophisticated gambling, at least you’re not sitting in the smoky haze with eyes glazed over at a shiny slot machine, but it’s still gambling. The little news tidbits aren’t going to help you beat the market, nor will the pretty charts. The truth is that even professionals don’t beat the market. The beauty and ease just make it more tempting.
Robinhood will you trade options, which is an even riskier way to invest, and even more likely to lose you more money. An option is just a leveraged bet on the market, like putting your money on 13 at the roulette table. It’s a terrible idea. - Robinhood offers free trades, perhaps its most alluring selling point. Purchasing stocks always involves fees, brokerage fees, trade commissions, transaction fees, etc. Brokers who conduct trades charge fees, usually per transaction. Robinhood is one of the few places where consumers can purchase shares without transaction fees. So it’s beautiful and free? Who says no to that?
It’s not entirely free. There are regulatory fees on every trade which Robinhood does pass on to customers. These fees are typically fractions of pennies, and Robinhood rounds them up to the nearest penny, pocketing the round-up of course.
Robinhood also generates substantial income from a practice called ‘payment for order flow,’ a controversial industry practice interestingly invented by Bernie Madoff. It basically means Robinhood sells the right to execute customer trades to third-party market makers who pay a small fee. Those small fees add up, and Robinhood relies on their high-frequency traders to make it work. Regulators don’t love it, in fact, other brokers and market makers have faced lawsuits over the issue. Robinhood’s dependence on this income could spell its downfall in the coming years. - Robinhood only allows you to buy entire shares, which are often pricey. At the time of this writeup Apple is trading at around $200/share, SPY (a very popular ETF that tracks with the S&P 500 index) is trading at about $300/share, Tesla is at $220, you get the idea. Not all shares are that expensive, but it’s tough to deposit a small amount and get trading, you need more money to buy full shares.
It’s not like Robinhood couldn’t offer partial shares, other platforms do it. Robinhood doesn’t because this is another one of the ways they make money. Offering full shares exclusively means that you will usually have some leftover change in your account, and Robinhood earns interest on those leftover funds. It also encourages you to invest larger chunks of money, which means you’re likely to lose more money.
I’m not saying you’ll die young or retire destitute if you invest some money in Robinhood. But just be aware of what you’re doing. You’re gambling. For the most part, it’s best to stay away.
Are you market timing?

Market timing is the practice of moving money in and out of the market, or in and out of specific sectors of the market, based on a belief that the market, or specific sectors of the market, will do well (in which case you’d be in) or poorly (in which case you’d pull out) in the future. If you’ve read about stock picking, market timing might sound familiar. Market timing is similar because it’s also built on a false premise that the market is inefficient, but it’s also a little bit different. Market timing is more subtle than stock picking. Instead of a belief that you can buy underpriced stocks and sell overpriced stocks, market timing is a larger bet on the future of entire market sectors. It gives the allusion that you can simultaneously be well-diversified and engage in market timing since you might always own a few different asset classes. It’s sort of like stock picking in disguise (it’s often called ‘tactical asset allocation’ which sounds super smart) because it’s essentially picking market sectors (asset classes) instead of stocks. Market timing can seem more legitimate than stock picking, but it’s still essentially gambling.
Market timing is unfortunately just as pervasive in the investing world as stock picking. It is often incited by panic, people move their money around or out when the market seems especially scary and move it back again (or not) when the market feels more safe. The timing tends to be exactly opposite of what should be done, people end up selling low and buying high and sacrificing millions of dollars in returns. But damage is done apart from panic too. Dalbar (an investor research company) reports that the average equity (stock) fund investor stays invested in their funds for only 4 years before jumping to a different set of funds, perhaps unintentionally market timing. Money managers routinely shift strategies within popular mutual funds (referred to style drift), shifting focus between market sectors. Pundits constantly discuss market trends which include market timing suggestions. Similar to stock picking, we’re so immune to market timing that it just sounds like normal investing at this point. That’s bad, here are a few reasons why:
1) People are bad at market timing. A study by William Sharpe conducted in 1975 (Likely Gains from Market Timing) concluded that in order for a market timer to beat a passive fund they would have to guess right about 74% of the time. An update to the study by SEI Corporation in 1992 concluded that the market timer would have to guess right at least 69% of the time, and sometimes as high as 91% of the time in order to beat a similarly invested passive fund. So the important question is: does anyone guess right with that frequency? Maybe you’ve made your own guess by this point, the answer is a resounding no. CXO Advisory did a fascinating study on the success ratios of market timers between 2005 and 2012. They looked at 68 ‘experts’ who made a total of 6,582 predictions during that period. The average accuracy of all predictions? 46.9%, well short of the minimum 69% threshold. These predictions sell news subscriptions and online adds, but they’re detrimental to investor returns.
2) Market timers miss out on returns. Trends are a big topic in the world of investing. Market timers analyze previous trends, they track current trends, and they look for the next trend, it’s incessant. Nejat Seyhun in a 1994 study entitled “Stock Market Extremes and Portfolio Performance” analyzed the period between 1963 and 1993 (a total of 7,802 trading days) and found that only 90 of the days were responsible for 95% of the positive returns. That’s about 3 days per year on average where 95% of returns came from. In all the misguided ‘trends’ talk and the popular practice of moving money in and out and all around, market timers routinely miss the most rewarding days in the market. Instead of focusing on market trends, investors would do much better to focus on the whole market and ride the general stint of the market upwards.
3) Market timers misunderstand the market. The most culpable cause of market timing is panic. People do crazy things when they’re scared and their money is on the line. Don’t get me wrong, the stock market can seem pretty scary, and it definitely involves money, but just because it seems scary doesn’t mean you should be scared. The average market crash of 10% or more lasts just under 8 months, 4 months until it hits the bottom, and just under 4 months to return to the pre-crash high. That’s not so scary. Over the last 93 years (going back as far as we have super-reliable data) 68 years were positive by an average of 21%, 25 years were negative by an average of 13%. Also not so scary. There are 45 countries in the world with free markets and the ability to buy and sell stocks and over 17,000 companies to invest in. What would it take for a well diversified portfolio to lose everything? Only some type of global apocalyptical event, at which point you probably wouldn’t be concerned with the amount of money in your portfolio. That is scary but not because of the market, it’s actually pretty reassuring as far as your portfolio is concerned. Instead of panicking, investors would do much better to rebalance during turbulent markets and capture returns on the way back up.
So market timing is a losing game. It can’t provide any consistent value to a portfolio, it actually causes a drag on returns, and it’s often driven by an inaccurate understanding of the market. Unfortunately it’s prevalent, and many portfolios engage in market timing while investors remain unaware. So take a look, have an advisor do an analysis for you. It pays to understand how you’re invested and to avoid market timing in your portfolio.
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Part 4: Conclusion
All of the information used to identify where returns come from is historical data. The data shows us how asset classes behave relative to each other (correlation), how much risk (volatility) is associated with each, and how much return we can expect over long periods of time.
But, it’s important to distinguish between what history can and cannot show us. While historical data does show us how the market works and how we can be ideally diversified to capture returns, it does not tell us which specific stocks or asset classes will be up or down from year to year or anytime in the future. It’s popular practice to analyze data and trends in an attempt to predict what the market will do next, many investors even expect that type of prognostication from their advisor. The problem is that humans simply can’t predict the future. As much as we like to think we can beat the market, the best we can hope for is to guess correctly, which is much more like gambling than investing.
Based on what we know about the market, we can capture amazing market returns with some discipline and patience. We know the market is efficient so it’s useless to try to predict or beat it (part 1), we know we can reduce risk and increase returns with strategic diversification (part 2), and we know that certain asset classes outperform others over time (part 3).
By understanding and putting these principles to work as an investor, you can stop stressing, stop guessing, and let the market grow your money.
Instead of making a guess as to what the market will do next year, put yourself in the best possible position to capture the returns it will offer, whichever sector they come from.