Is January Really the Best Month for Stocks?

Every January investors will say things like “January is the best month for stocks” or refer to “the January effect.” Articles will crop up about how “last year was all about January,” implying January will repeat its dominance.

January sounds nice and neat. Jump out to a big January return and just enjoy the market ride for the rest of the year.

Does it really work like that though?

Or is January surrounded by more folklore than reality?

Let’s take a relaxed look at the evidence behind January. No hype, just facts. I want to explore where this “January is best” myth comes from, review what the data actually shows, and discuss how you should view January as part of your overall investment strategy.

---

A Look Back: Where Did January Come From?

Believing January is special isn’t arbitrary. The “January Effect” has been observed and discussed by academics and financiers for many years.

Empirically, analysts noticed that January (especially January for small-cap stocks) was often a stronger performing month than the rest of the year. There were many theories as to why this happened:

• Tax-loss selling. Investors sell losers at the end of the year for tax purposes. January 1 brings a release of that selling pressure.
• Portfolio rebalancing. Institutions often redeploy capital, invest fresh inflows, or reset risk targets for the new year. That can result in buying.
• Simple psychology. January is a fresh start with new goals and often new money entering retirement accounts. January may start off optimistic.

Anyone can rationalize why January might be different. But historically different does not always mean predictive or statistically significant.

---

Looking at the Stock Market Data

When you actually look at stock market data over many decades, January is rarely the best month.

It is usually positive. During particularly bullish decades, January has occasionally been the best month on average. But April, November, and December have also been the best month many times.

More importantly, look at how wide the range of outcomes is. January can be very strong. January can be flat. January has also seen some of the worst market drops in history. Many times when January has stumbled, the rest of the year made up for it with strong returns. Other times January was great but the market still collapsed later that year.

If you want to pick one month every year to invest based on, it sure isn’t January.

January does have a very mild positive bias if you look at a lot of historical data. But it’s slight. It’s inconsistent. And it depends heavily on which time period you study.

It’s also not something you can base an investment strategy on. The edge just isn’t there anymore.

---

The January Barometer

Some investors like to refer to January’s performance as the “January barometer.”

“As January goes, so goes the year.”

It sounds cool, and sometimes it works. Every year there are stories of strong Januarys leading to strong full-year performances. The same goes for weak Januaries.

But when you look at the full history, it’s impossible to rely on.

Take a look at these partial tear sheets of January stock market performances:

• 2021: Down over 6% in January yet ended the year up over 26%.
• 2016: Down over 5% in January yet ended the year up over 11%.
• 2011: Up over 7% in January yet ended the year down over 2%.
• 2020: Down over 11% in January yet ended the year up over 16%.

Do you see a pattern here?

Hell, just look at 2021. January was brutal. Then markets rallied hard for the rest of the year.

One month does not — and should not — dictate your view of the market for the next 11 months.

Nothing that happens in January completely controls the rest of the year’s trend.

---

January Doesn’t Matter THAT Much

Aside from potential recency bias, January is often given more credit because it’s easy to weave a narrative around.

If January is up, everybody headlines “bullish start to year signals strong 2024!” If January is down, they say the opposite.

Humans love stories, and January works as a nice storytelling anchor because it’s the beginning of the calendar year. But the markets couldn’t care less about your calendar.

Earnings cycles, policy decisions, portfolio flows, they all follow their own schedule.

Another reason January is noisy is because of how investors are positioned going into it.

The beginning of the year is when a lot of people have new money to invest from 401(k) contributions or bonuses. There are flows happening that don’t necessarily happen other times of the year. That can create more volatility and draw attention.

Just because volatility is there, doesn’t mean it’s predictive.

---

The January Effect Is Real but Weakens Over Time

This is important.

When a market anomaly (like January) becomes popular, it tends to fade over time as more investors become aware of it and act on it early.

The January effect was far more reliable and powerful in past decades — especially when looking at small-cap stocks.

With modern transaction costs, algorithmic trading, global capital flows, and instantaneous news/discovery, there simply is not as much of a January effect to exploit.

If anything is left, it’s a subtle edge at best.

---

Factors That DO Matter More Than January

Instead of getting caught up in January, pay attention to what will actually impact your portfolio for the long-term.

• Interest rates. Interest rate changes can drive markets for years, regardless of January’s performance.
• Earnings revisions. Stock prices tend to follow earnings over long periods of time. One month doesn’t invalidate an entire earnings cycle.
• Valuations. Where the market starts matters. You still wouldn’t buy insanely overvalued markets just because January was great. Same thing for avoiding insanely overvalued markets if January was bad.
• Market liquidity. Investors’ cash positions and how they’re positioned can influence markets far more than the calendar.
• Risk management. Preventing large drawdowns is far more important than market timing one month of the year.

January can be educational, but the real meat lies in other factors.

---

The Smart Investor’s Approach to January

As an investor, I like to view January as informational, not a make-or-break factor.

If we see strong returns in January, I ask myself:

• Are earnings being revised higher?
• Is liquidity coming into the market?
• Are rates/inflation expectations shifting?

If we see poor returns in January, I ask myself:

• Are we seeing a correction of overly bullish positioning?
• Are fundamentals worsening? Or is this simply noise?

January won’t force me to make major changes to my long-term asset allocation.

Normally, if January is bad that’s when the opportunities are created. Smart investors buy low and sell high. Pessimism in January can lead to the best buying opportunities of the year. The same can happen if people become too greedy in January.

---

Should You Be More Aggressive in January?

For the vast majority of investors, no.

Trying to overweight in January is basically market timing based on a calendar. You’re guessing the markets will do you favor based on months. There’s no statistical reason to be confident that will work year after year.

What you can do instead is:

• Stay diversified and allocated how you like throughout the year.
• Rebalance when prices change, not when your emotions change.
• Buy additional shares when prices are low, valuations are attractive, and sentiment is pessimistic. (January is often a great month to do this, but that’s only because many investors think you CAN’T buy in January.)

If you dollar-cost invest through your 401(k) plan, January is just another month where you invest. There’s no reason to place special weight on it.

---

January: Myth? Mild Edge? or Just Foolish?

So, is January really the best month to own stocks?

The truthful answer is: kind of, but not really.

January has historically been positive more than not due to some logical explanations. But the edge it provides is small, practically nonexistent in recent decades, and not predictive.

January is fun to talk about, and it can sometimes give you clues about investor sentiment, market positioning, and macro conditions. By all means, learn from January’s performance. But don’t let a month overpower your overall strategy.

What matters more is sticking to your plan, managing risk, and thinking about the long-term instead of what happens in January or any other single month.