<div id="readability-page-1"><p>Breadth has been a hot topic during the stock rally over the last six weeks. Critics and bears suggest the fact that a small number of large cap stocks are driving the rally means it can’t be sustained and/or increases the likelihood of a pullback.</p> <p>Comparing the S&amp;P 500 Index (SPX) to the Equal-Weighted SPX gives us a good idea about how the large cap stocks are performing compared to the smaller companies. The SPX is weighted by market capitalization so that larger companies have more influence over the movements of the index. The Equal-Weighted index gives equal weight to each company.</p> <p>The chart below shows the year-to-date return of the SPX and the Equal-Weighted SPX. Through late March, the Equal-Weighted index outperformed the SPX significantly. The SPX was down almost 8% for the year while the Equal-Weighted index was down less than 2%. However, the SPX has come roaring back over the past six weeks to overtake the index. This week I’ll be looking at how stocks perform after huge rallies based on how the SPX performs compared to the Equal-Weighted index.</p> <p><img src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/spx-v-equal-weigh.jpg/query-c2Z2cnNuPTQ3NWViZDA2XzI?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" width="648" height="460" original-src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/spx-v-equal-weigh.jpg/query-c2Z2cnNuPTQ3NWViZDA2XzI"/></p> <h2>Six-Week Relative Strength</h2> <p>Going back to 1975, I recorded daily data on the six-week relative strength of the Equal-Weighted index to the SPX. Then I found dates that the SPX was at an all-time high and I broke those down into three groups based on the relative strength.</p> <p>The first table shows our current situation. It shows the times the relative strength of the Equal-Weighted SPX was low (specifically, below 0.98) and the SPX was at an all-time high. Based on this, the bears have a point, especially in the shorter term. In our current situation, for the next month, the SPX averaged a loss of 0.92% with 54% of the returns positive. When the relative strength of the Equal-Weighted index was high (above 1.01), the SPX averaged 1.04%, with over the next month with 72% positive. When the relative strength has been more moderate at all-time highs, the returns are in between those. This pattern holds for the three-month returns. The longer-term returns (six and 12 months) are more mixed.</p> <p><img src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/spx-ath-equal-weight.jpg/query-c2Z2cnNuPTdmNWViZDA2XzI?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" width="549" height="881" original-src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/spx-ath-equal-weight.jpg/query-c2Z2cnNuPTdmNWViZDA2XzI"/></p> <h2>Extreme Relative Strength </h2> <p>Over the past six weeks, the SPX index outperformance against the Equal-Weighted index has been extreme. Over the past few days, the relative strength of the Equal-Weighted index has been below 0.95. That’s lower than 99% of the readings going back to 1975.</p> <p>The table below summarizes the returns after the Equal-Weighted SPX relative strength falls below 0.95 for the first time in at least a month. There have only been 13 other occurrences. The SPX has performed well after these instances across each of the time frames. The SPX has averaged a return of over 2% over the next month and over 18% for the next year after these instances with 85% of the returns positive. Compare that to the typical one and six-month returns of 0.85% and 10.2%.</p> <p><img src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/spx-rsi-equal-weight.jpg/query-c2Z2cnNuPTRiNWViZDA2XzI?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" width="575" height="607" original-src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/spx-rsi-equal-weight.jpg/query-c2Z2cnNuPTRiNWViZDA2XzI"/></p> <p>This next table shows how the Equal-Weighted index performed after these extremely low relative strength readings. The returns from this index have also done well after these instances. Six months after these signals, the Equal-Weighted index gained over 12% on average with 92% of the returns positive.</p> <p><img src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/equal-weight-spx.jpg/query-c2Z2cnNuPTQzNWViZDA2XzI?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" width="576" height="298" original-src="https://imageproxy.pbkrs.com/https://schaeffers-cdn.s3.amazonaws.com/images/default-source/schaeffers-cdn-images/2026/may/iotw/equal-weight-spx.jpg/query-c2Z2cnNuPTQzNWViZDA2XzI"/></p> <p>In conclusion, the fact that a small portion of large-cap stocks have outperformed compared to the rest of the market is not, by itself, a bearish signal. Stocks have tended to do well after extreme cases like we’ve just seen. However, the first part of this article showed when the market has been at all-time highs, it has been more bullish going forward when more stocks participate in the rally.</p></div>

标普 500 指数

标普 500 等权指数 ETF - Guggenheim

URSP

标普 500 ETF - Vanguard

标普 500 ETF - iShares

标普 500 ETF - SPDR

<p>最近的股市反弹引发了对市场广度的担忧，批评者认为大型股的主导地位可能不可持续。对标普 500 指数（SPX）与等权重 SPX 的分析显示，尽管 SPX 近期表现优于等权重指数，但历史数据表明，当推动反弹的股票数量较少时，未来的回报可能不太理想。然而，SPX 在极端相对强势的过去实例中也曾带来积极回报，这表明当前的情况不一定意味着看跌趋势</p>

Are Large Caps Really Leading This Rally? A Market Breadth Study

- 股票反弹期间，小型公司表现落后于大型股。  
- 在相对强度低于 0.95 时，SPX 平均回报超 2%。  
- 市场高位时，多数股票参与反弹更为积极。

大型股是否真的在引领这次市场反弹？市场广度研究