Can’t sleep? Check your lights

I’ve talked with many traders who struggle from insomnia or other sleep disruptions. There could be many reasons for this. Some, such as the emotional pressures of trading, are obvious, but I think there is another common culprit: the light we use.

All light is not the same

Light is a kind of electromagnetic (EM) radiation that we can see. The EM spectrum covers a wide range from gamma rays to x-rays, through visible light, then through infrared, microwave, and radio waves at the other end. Our eyes are only sensitive to a small range of this spectrum, and we perceive different wavelengths as different colors.

White light, as we all learned in school, is a mixture of all colors. (Specifically, mix red, green, and blue lights and we get white.) However, it’s not quite that simple. I’m sure you’ve noticed that colors look strange under certain lights. For instance, parking lot lights (often high pressure sodium bulbs) give a yellowish light that makes everything look grey—you often can’t tell a green from a blue from a red car in a parking lot at night. This is because different kinds of white light have different properties; this has a direct effect on how we see and may have other effects that are less obvious.

Color temperature

kelvin_temperature_chartOne of the most important things to consider with white light is the “color temperature” of the bulb. Color temperature may be confusing at first, but that’s because we use the labels “warmer” and “cooler” in two contradictory ways—it is confusing! Technically, when we heat something up it starts to glow red, then orange, then white, and eventually blue; so the hotter the thing the “bluer” it is. Bulbs are labeled with a temperature in Kelvin that corresponds to the temperature a black body radiator (think a wire filament) would glow at that temperature. Most bulbs fall somewhere in a range: 1700K is a very orange light, like a candle flame, and 6500 is a very bright blue like daylight.

The confusion comes because we refer to “oranger” light as “warmer”, which is exactly the opposite of the technically correct Kelvin temperature scale. So, blue lights (for instance, fluorescents) are cooler whites and the light bulbs we all grew up with are warmer. Why does this matter?

Light, sleep, and work

We live in very artificial and controlled environments today, but our bodies evolved within the cycles of the natural world—in particular, seasons and the day/night cycle shaped much of human existence and society. We know that people who live in extreme polar regions where the natural alternation of day and night is disrupted also experience extreme sleep disruptions, and evidence is beginning to pile up that exposure to artificial light is changing our cycles in ways we don’t fully understand yet. I’ll share my personal experience here, which is that taking control of your light can change a lot of things about the way you feel, the way you work, and the way you sleep.

Simple solutions

The easy solution really is simple: just start turning some lights off or dimming them a few hours before you want to sleep. Simple things can make a pretty big difference, and this is one of those things. If you can simply avoid staring into bright lights before sleepy time, you’ll probably sleep better.

The next step is only a little more complicated. First, install some software on your computer: f.lux is one of the best things I have started using in the last year. It’s a completely free, simple program that knows when the sun sets (once you tell it where you are in the world) and changes the color temperatures of your computer screens at night. If you happen to be staring at the screen when the sun sets (as, alas, I usually am) you’ll notice it turns a little orange at the time, but your eyes quickly adjust and you won’t even notice it. F.lux will work on all your computers and most of your tablets. The iPhone has a similar solution, and Android isn’t far behind. You’ll need to take a few minutes to configure the colors you want, but the program will then run seamlessly in the background. (An important word of advice: if you do color-sensitive photography work, make sure you disable the app while you edit photos at night!)

You could also pay attention to the color temperatures of the light bulbs you buy. Simply tilting toward warmer lights (say in the 2700K – 3000K) and avoiding the daylight bulbs will help you avoid exposure to the wavelengths that potentially disrupt sleep. But, if you want to do something really cool, there’s an even better way, and now’s a good time to do it.

The best solution

Over the past year, I’ve replaced virtually every light bulb I have with Philips Hue LED bulbs. These bulbs are energy efficient, run completely cool, and, theoretically, last many years. You can start replacing the bulbs you have a few at a time to minimize the upfront investment, but end of year deals make all of this much more affordable.

You do need a hub to run the Philips Hue system, and the best way to get started is with a few bulbs and the hub. Installation was seamless and easy into my wifi system, literally taking less than 5 minutes to set up. The Hue hub can control bulbs from many manufacturers, but I’ve tried a few and I do really like the Hue bulbs. Be aware that these come in three versions: There’s one that is simply dimmable. These are cheap and may be good in some parts of your home, but I’d go with one of the others for the options they offer.

There is a version of the bulbs that can dim and change color temperatures from very warm lights to almost piercing daylight. These are called White Ambiance, and currently run just under $29.99 per bulb. Yes, I realize sticker shock is a factor here, but there is also a very real reduction on your electric bill, and you’re likely to have these bulbs for a decade. If you want to go all-out, there is another bulb that can do all the whites and a wide range of colors. These are called White and Color Ambiance and run about $10 more. (There’s a third generation out that has even better colors. I have some 2nd and 3rd gen bulbs, and the 3rd gen, in my opinion, are worth the extra cost for rich blues and greens.)

These bulbs work well with the Amazon Echo. I’ve been a user of the Echo since the early days, and it’s one of the most useful gadgets I’ve seen in years. From calendar management to news to reminders to, now, changing the brightness and colors of the lights in each room, you can do all of this with your voice. The problem you might have is that anyone who comes over to your place and sees that you can control your house with voice commands will probably go home and buy some toys for themselves. If the Echo is a little bit more than you want to spend right now, the smaller Echo Dot (functionally the same but with a speaker that sounds more like a smartphone than the Echo’s quite passable Bluetooth speaker) is very affordable with holiday discounts.

A shopping list?

Aside from the occasional book, I don’t usually plug products in my blog posts, but these lights (and the Echo) have made such a fundamental difference in how I live and how I work that I wanted to share them with you. I’ll write a post in a few days about how to put this all together and what to do with it, but these “toys” are likely to be on pretty big discounts for the next month, so I wanted to get you started watching prices! Also, I don’t sell ads or make any money from this blog, but I do get a small “commission” when you use the links above to do your Christmas shopping. In fact, if you buy one of those items and then do more shopping, I get a little commission from all your shopping! This helps support this blog and keeps the lights on, so I do thank you for your support.

A few years ago if someone told me that light was important and that I should think about light, I would have dismissed them completely. Today, I’m a complete convert and I’ll tell you more about why in a blog post soon.


Adam Grimes has over two decades of experience in the industry as a trader, analyst and system developer. The author of a best-selling trading book, he has traded for his own account, for a top prop firm, and spent several years at the New York Mercantile Exchange. He focuses on the intersection of quantitative analysis and discretionary trading, and has a talent for teaching and helping traders find their own way in the market.

This Post Has 3 Comments

  1. hawaiianwaverider

    Good information Adam. For android, I use and like twilight. Easily adjustable times, colors etc.

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