Although capitalization-weighted index funds are the industry standard, there are several advantages to equal-weighted index funds that make them worth a close look for adding to your portfolio.
The main advantage, simply, is that evidence suggests that the equal weighted ones generally produce superior returns.
But the reasons why are complex, and there are several specific advantages and disadvantages, so this article explores them in detail to help you pick which ones are right for you.
What are Equal Weighted Index Funds?
A stock market index tracks a certain set of publicly traded companies, and the vast majority of these indices are weighted in terms of market capitalization. The market capitalization of a company is the sum value of the price of all of its shares.
Just about any S&P 500 fund you invest in puts a greater percentage of its money into very large companies compared to smaller companies on the index. Apple has a far bigger market capitalization than American Express, for example, and so the S&P 500 invests far more heavily into Apple despite the fact that they are both members of the index. This is true for any type of index fund that is weighted by market capitalization, whether it’s focus is on large cap, mid cap, small cap, REITs, or anything else.
In fact, although the S&P 500 consists of, as you might guess, about 500 companies, the top 10 holdings in the list make up nearly 20% of the entire index.
An equal-weighted index fund, on the other hand, takes the same set of companies, and invests in them as equally as it can. An S&P 500 equally weighted index, for example, puts the same amount of money into Apple as it does into American Express. It’ll put about the same amount of money into all of the companies in the index, regardless of their relative size.
Momentum vs Value
Indices that are weighted by market capitalization are inherently momentum-based. When a stock starts increasing in share price, the indices automatically begin increasing its weighting in the index, and so index funds start buying more of those shares.
Likewise, when a stock starts decreasing in share price, the indices decrease their weighting, and index funds start selling those shares.
Therefore, cap-weighted index funds are heavy buyers of stocks that are already going up in price, and are heavy sellers of stocks that are already declining. That makes them momentum-based.
In contrast, indices that are weighted equally are inherently value-based. The index fund is divided equally between all companies that are included in the index, so when shares of company A go up and shares of company B go down, the fund has to sell some shares of Company A and buy some shares of Company B in order to balance it equally again.
It’s more contrarian, more of a passive value investing approach, buying out-of-favor companies and selling the popular ones.
Performance of Equal Weight Indices
Here are three case studies comparing how equally weighted indices compare to their more typical market capitalization weighted cousins.
Case Study #1: Equal Weighted Wilshire 5000
The biggest dataset that I’m aware of for the performance of equal weighted indices is from Wilshire Associates. You can download the performance data for all of their indices here.
The Wilshire 5000 is the best representation we have of the United States stock market. It tracks almost all publicly traded companies in the United States from small cap through mega cap companies, except for penny stocks and other tiny companies.
Using Wilshire’s data, here’s a chart of how the equal weighted version has performed over almost 50 years compared to the market capitalization weighted version:
This is an index rather than an actual fund, but hypothetically for every dollar you invested into the standard Wilshire 5000 market capitalization weighted index at the end of 1970, you’d have more than $102 by the end of 2016. The blue line looks almost flat on that graph, but it increased by over a hundred-fold, and produced about a 10.5% annualized return.
However, the orange line utterly dwarfs it. For every $1 you put into the Wilshire 5000 equal weight version of the index at the end of 1970, you’d have over $1,458 by the end of 2016. That’s an order of magnitude superior returns over nearly a 50 year period, and equals about 17.1% annualized returns.
Plus, the equal weighted version outperformed every single decade. So, although it was more volatile, its outperformance was consistent decade after decade without fail.
There are, however, some major caveats:
- There’s no way to directly invest in the Wilshire 5000 equal weight index.
- The equal weighted version would have had significantly higher turnover, and thus higher fees and less efficient taxation.
Still, we’re talking 14x better performance as the baseline, for a huge set of companies over an extremely long timeline.
Case Study #2: Equal Weighted S&P 500
The previous example was hypothetical, but this one is practical.
The Guggenheim S&P 500 Equal Weight ETF (ticker: RSP) was launched in 2003. It has about $13 billion in assets under management and has an expense ratio of 0.40%.
Here’s how it has fared compared to the SPDR S&P 500 Trust ETF (ticker: SPY), which is a cap-weighted index with $229 billion in assets and an expense ratio of 0.0945%, courtesy of Google Finance:
The blue line is the equal weighted index ETF while the red line is the cap weighted index ETF.
This one is closer, and we only have 13 years of data, but so far, the equal weight one is significantly outperforming. Even after you account for the higher expense ratio and the fact that its distribution yield is a few tenths of a percent lower, the outperformance is still meaningful. Especially if you extrapolate this over a 40 year investing career until you retire.
However, note that in 2009, the drawdown of RSP was significantly bigger, and was enough to bring it down to the level of the standard index. It’s possible that the next market correction will bring it lower towards the other one again, at least temporarily.
Since equal-weighted indices are less focused on mega-cap companies and have a bigger mid-cap base, they’re more volatile and may provide better overall returns. They fall more severely during recessions but rebound more strongly during bull markets.
Case Study #3: Equal Weighted NASDAQ 100
There’s an equal weight ETF of the NASDAQ 100, called the Direxion NASDAQ-100 Equal Weighted Index Shares (ticker: QQQE).
This is their performance compared to the standard NASDAQ index:
Over a decade-long period, the equally weighted version has underperformed relative to the standard capitalization weighted version, which makes this example different from the prior two.
Since the NASDAQ 100 is dominated by technology, it could be that technology is simply different than other sectors when it comes to this. Many of the largest IT companies benefit from the network effect or from massive scale, meaning the more people that use their services the better the service becomes. Maybe cap-weighting is the way to go here.
Or it could just be luck with a fairly small sample size. The cap-weighted version dis-proportionally benefited from the rise of Amazon, Apple, Facebook, and Alphabet. Perhaps the massive ascendancy of just these four companies in this particular decade is an anomaly that made the cap-weighted version outperform the equal-weighted one.
We don’t have enough data to say yet.
Pros & Cons of Equal Weighted Indices
Although equal weighted ones may or may not have truly better performance, especially when you stick to the broad market or the S&P 500, there are definitely some trade-offs.
- Under the largest sample sizes, their long-term performance appears to be superior.
- They’re more diversified, rather than heavily concentrated into just the largest companies of the index.
- They naturally take a value-approach, which some investors prefer.
- They have higher turnover, which leads to higher expense ratios and generally higher capital gains taxes.
- They’re more volatile, and can fall more sharply during recessions.
- They’re only available for certain indices, because they’re not as popular yet.
- There are some interesting anomalies. For example if Apple were to split into two companies, a cap-weighted index would still have the same amount amount in it because the two parts would have about the same market cap when added together, while an equal-weighted one would double its exposure to it because it’s now two names and would invest in each equally.
- Changing the way the index is weighted changes the sector balance. Here’s an example for the S&P 500:
As you can see, the main difference is that the cap-weighted (SPY) version is far more weighted into IT. This is neither particularly good or bad in principle; it’s just another difference to be aware of.
And this can vary over time. Right now, Amazon, Facebook, Apple, and Alphabet are driving the bulk of that difference.
One takeaway from this may be that, at least in a broad sense, equal weighted index funds are simply better for building wealth over the long-term if you can withstand the added volatility. In that sense, the strategy is simply to buy and hold them instead of the market capitalization weighted varieties.
A more subtle approach is to invest in RSP at the bottom of a market cycle after a big correction, and invest in SPY when markets are expensive, as measured by the Shiller PE Ratio or some other metric. The data we have, both looking at large caps vs mid caps and from looking at equal weighted indices vs cap weighted indices, is that the cap weighted indices that have a bigger focus on larger companies tend to hold up better during market corrections, while the equal weighted varieties with a more balanced large/mid cap spread tend to fall more sharply. Inversely, the equal weighted ones recover more strongly from market bottoms.
And if you’re an option-seller, either with cash-secured puts or covered calls, then the additional volatility of the equal weighted indices can be turned from a disadvantage into an advantage. For option-sellers, all else being equal, higher volatility means higher premiums. Note: they have lower liquidity than standard index ETFs, which means bigger bid/ask spreads, and this can be a real problem during times of low volatility.
Personally, the only equal weight ETF that I occasionally use is the Guggenheim equal weight S&P 500 (RSP).