美國股市在過去幾天經歷了劇烈波動，最初對大型科技公司財報的樂觀情緒推動標普 500 指數創下盤中新高，但隨後對財報的失望反應以及美聯儲決定維持利率不變導致標普 500 指數急劇回落。
科技股的回調和 向小盤股的輪動 是 2026 年初主要的市場主題。截至 2026 年 1 月 28 日，標普小盤股 600 指數的表現超越標普 500 指數 4%，得益於強勁的經濟增長和穩健的企業盈利。
隨着收益的廣度開始超越大型股領頭羊，現在可能是審視等權重策略的有趣時機，這種策略在設計上偏向小盤股，並提供比市值加權同行更廣泛的市場覆蓋。
圖表 1 顯示，標普 500 等權重指數在截至 2026 年 1 月 28 日的三個月內 超越市值加權的標普 500 指數 3%，這與市場集中度的下降相吻合，自 2025 年第三季度以來，標普 500 前 10 家公司總權重已降至 40% 以下。
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<img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-1-Equal-Weight-Has-Outperformed-and-Concentration-Has-Declined.jpg?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" alt="" original-src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-1-Equal-Weight-Has-Outperformed-and-Concentration-Has-Declined.jpg"/>
值得注意的是，市場參與度已超越大型股名稱。 在 11 月初集中度達到峯值後，標普 500 的表現來源已在市值範圍內發生變化。圖表 2 顯示，儘管前 100 家公司在 2025 年大部分時間內佔據了指數收益的主要部分，但由於大型股的疲軟，它們的貢獻自那時起顯著下降，超額收益已轉向底部 400 家公司。
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<img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-2-Contribution-to-SP-500-Performance-Has-Broadened-.jpg?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" alt="" original-src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-2-Contribution-to-SP-500-Performance-Has-Broadened-.jpg"/>
行業層面的動態進一步解釋了這一轉變。在標普 500 等權重指數與標普 500 的 Brinson 行業歸因中，圖表 3 顯示，標普 500 等權重指數在去年大部分時間的表現不佳以及隨後相對於標普 500 的超額表現主要是由於在信息技術領域的低配， 這與該行業近期的困境一致。
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<img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-3-Underweight-to-Information-Technology-Has-Been-a-Tailwind-for-Equal-Weight-Outperformance.jpg?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" alt="" original-src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-3-Underweight-to-Information-Technology-Has-Been-a-Tailwind-for-Equal-Weight-Outperformance.jpg"/>
標普 500 等權重指數的因子特徵也發揮了支持作用。除了其小盤股偏好外，標普 500 等權重指數歷史上還持續傾向於價值股，而非動量股， 因為該策略的定義是定期從相對贏家中再平衡到相對輸家。這些因素受益於市場廣度的改善以及對大型成長股和動量股的輪動。值得注意的是，標普 500 價值股的表現超越了標普 500 成長股，而標普 500 動量指數在 1 月份迄今表現不及標普 500 指數 2%。
圖表 4 顯示，標普 500 動量指數極端相對超額表現的時期往往會被標普 500 等權重指數的超額表現所跟隨， 反映了這兩種方法之間自然的反向關係。考慮到標普 500 動量指數在 2025 年的卓越表現，這一歷史趨勢可能特別相關。
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<img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-4-SP-500-Momentum-Index-and-SP-500-Equal-Weight-Index-Are-Inversely-Related.jpg?x-oss-process=image/auto-orient,1/interlace,1/resize,w_1440,h_1440/quality,q_95/format,jpg" alt="" original-src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-4-SP-500-Momentum-Index-and-SP-500-Equal-Weight-Index-Are-Inversely-Related.jpg"/>
如果大型科技公司面臨的逆風持續惡化，市場廣度的增加和對大型股的輪動可能會持續。我們知道，極端市場集中後的時期歷史上與標普 500 等權重指數的超額表現相吻合，市場參與者理解該策略相對錶現的來源和驅動因素可能是有益的。
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1《華爾街日報》，“小型股票創下週記錄”，2026 年 1 月 16 日。
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更多來自此作者的文章：
時尚的晚週期：標普 500 市場領袖指數
閃閃發光的不僅僅是黃金：2025 年主題表現回顧
休斯頓，我們有一個指數：探索標普 Kensho 全球太空指數

美國股市經歷了波動，最初由於大型科技公司財報帶來的樂觀情緒推動標普 500 指數創下新高，但隨後因財報失望和美聯儲維持利率而急劇下跌。2026 年 1 月，標普小盤股 600 指數的表現超越標普 500 指數 4%，顯示出對小盤股的偏好轉變。標普 500 等權重指數的表現也優於市值加權指數，反映出市場參與度超越了大型股。如果大型科技公司面臨的挑戰持續，這一趨勢可能會繼續，暗示投資策略可能發生轉變

U.S. equity markets have been whipsawed in the past few days, with initial optimism surrounding Big Tech earnings powering the S&amp;P 500® to an intraday high, and subsequent disappointing reactions to earnings coupled with the Fed’s decision to hold rates steady leading to a sharp retreat for The 500®.
<div class="lb-trans">美國股市在過去幾天經歷了劇烈波動，最初對大型科技公司財報的樂觀情緒推動標普 500 指數創下盤中新高，但隨後對財報的失望反應以及美聯儲決定維持利率不變導致標普 500 指數急劇回落。
</div>The pullback in Tech and the rotation toward small-cap stocks have been major market themes that have characterized the start of 2026.1 The S&amp;P SmallCap 600® has outperformed The 500® by 4% month-to-date as of Jan. 28, 2026, propelled by strong economic growth and robust corporate earnings.
<div class="lb-trans">科技股的回調和 向小盤股的輪動 是 2026 年初主要的市場主題。截至 2026 年 1 月 28 日，標普小盤股 600 指數的表現超越標普 500 指數 4%，得益於強勁的經濟增長和穩健的企業盈利。
</div>As the breadth of returns has started to expand beyond mega-cap leaders, it may be an interesting time to examine equal-weight strategies, which by design have a small-cap bias and offer a more broad-based footprint than their capitalization-weighted peers.
<div class="lb-trans">隨着收益的廣度開始超越大型股領頭羊，現在可能是審視等權重策略的有趣時機，這種策略在設計上偏向小盤股，並提供比市值加權同行更廣泛的市場覆蓋。
</div>Exhibit 1 shows that the S&amp;P 500 Equal Weight Index outperformed the capitalization-weighted S&amp;P 500 by 3% over the three months ending Jan. 28, 2026, coinciding with a decline in market concentration, with the aggregate weight of The 500’s top 10 companies falling below 40% since Q3 2025.
<div class="lb-trans">圖表 1 顯示，標普 500 等權重指數在截至 2026 年 1 月 28 日的三個月內 超越市值加權的標普 500 指數 3%，這與市場集中度的下降相吻合，自 2025 年第三季度以來，標普 500 前 10 家公司總權重已降至 40% 以下。
</div>(Click on image to enlarge)
<div class="lb-trans">(點擊圖片放大)
</div><img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-1-Equal-Weight-Has-Outperformed-and-Concentration-Has-Declined.jpg" alt="" original-src="https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-1-Equal-Weight-Has-Outperformed-and-Concentration-Has-Declined.jpg"/>
Notably, market participation has expanded beyond the mega-cap names. Following the peak in concentration in early November, the sources of the S&amp;P 500’s performance have shifted across the capitalization spectrum. Exhibit 2 shows that while the top 100 companies accounted for the majority of the index’s gains for most of 2025, mega-cap weakness has caused their contribution to decline considerably since then, as outperformance has shifted to the bottom 400 companies.
<div class="lb-trans">值得注意的是，市場參與度已超越大型股名稱。 在 11 月初集中度達到峯值後，標普 500 的表現來源已在市值範圍內發生變化。圖表 2 顯示，儘管前 100 家公司在 2025 年大部分時間內佔據了指數收益的主要部分，但由於大型股的疲軟，它們的貢獻自那時起顯著下降，超額收益已轉向底部 400 家公司。
</div>(Click on image to enlarge)
<div class="lb-trans">(點擊圖片放大)
</div><img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-2-Contribution-to-SP-500-Performance-Has-Broadened-.jpg" alt="" original-src="https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-2-Contribution-to-SP-500-Performance-Has-Broadened-.jpg"/>
Sector-level dynamics further explain this shift. In a Brinson sector attribution of the S&amp;P 500 Equal Weight Index versus the S&amp;P 500, Exhibit 3 shows that the S&amp;P 500 Equal Weight Index’s underperformance for most of last year and its subsequent outperformance relative to the S&amp;P 500 was largely driven by an underweight in Information Technology, consistent with the sector’s recent travails.
<div class="lb-trans">行業層面的動態進一步解釋了這一轉變。在標普 500 等權重指數與標普 500 的 Brinson 行業歸因中，圖表 3 顯示，標普 500 等權重指數在去年大部分時間的表現不佳以及隨後相對於標普 500 的超額表現主要是由於在信息技術領域的低配， 這與該行業近期的困境一致。
</div>(Click on image to enlarge)
<div class="lb-trans">(點擊圖片放大)
</div><img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-3-Underweight-to-Information-Technology-Has-Been-a-Tailwind-for-Equal-Weight-Outperformance.jpg" alt="" original-src="https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-3-Underweight-to-Information-Technology-Has-Been-a-Tailwind-for-Equal-Weight-Outperformance.jpg"/>
The S&amp;P 500 Equal Weight Index’s factor profile has also played a supportive role. In addition to its small-cap bias, the S&amp;P 500 Equal Weight Index has historically maintained a persistent tilt toward value and away from momentum, as the strategy, by definition, regularly rebalances away from relative winners and toward relative losers. These factors have benefited from improving market breadth and a rotation away from large-cap growth- and momentum-oriented stocks. Notably, the S&amp;P 500 Value has outperformed S&amp;P 500 Growth, and the S&amp;P 500 Momentum Index has underperformed The 500 by 2% so far in January.
<div class="lb-trans">標普 500 等權重指數的因子特徵也發揮了支持作用。除了其小盤股偏好外，標普 500 等權重指數歷史上還持續傾向於價值股，而非動量股， 因為該策略的定義是定期從相對贏家中再平衡到相對輸家。這些因素受益於市場廣度的改善以及對大型成長股和動量股的輪動。值得注意的是，標普 500 價值股的表現超越了標普 500 成長股，而標普 500 動量指數在 1 月份迄今表現不及標普 500 指數 2%。
</div>Exhibit 4 shows that periods of extreme relative S&amp;P 500 Momentum Index outperformance have often been followed by outperformance in the S&amp;P 500 Equal Weight Index, reflecting the naturally inverse relationship between the two approaches. This historical trend may be particularly relevant following the S&amp;P 500 Momentum Index’s stellar outperformance in 2025.
<div class="lb-trans">圖表 4 顯示，標普 500 動量指數極端相對超額表現的時期往往會被標普 500 等權重指數的超額表現所跟隨， 反映了這兩種方法之間自然的反向關係。考慮到標普 500 動量指數在 2025 年的卓越表現，這一歷史趨勢可能特別相關。
</div>(Click on image to enlarge)
<div class="lb-trans">(點擊圖片放大)
</div><img src="https://imageproxy.pbkrs.com/https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-4-SP-500-Momentum-Index-and-SP-500-Equal-Weight-Index-Are-Inversely-Related.jpg" alt="" original-src="https://www.indexologyblog.com/wp-content/uploads/2026/01/Exhibit-4-SP-500-Momentum-Index-and-SP-500-Equal-Weight-Index-Are-Inversely-Related.jpg"/>
If the headwinds facing Big Tech continue to worsen, the increase in market breadth and the rotation away from large caps may potentially persist. We do know that periods following extreme market concentration have historically coincided with the outperformance of the S&amp;P 500 Equal Weight Index, and it may be useful for market participants to understand the sources and drivers of the strategy’s relative performance.
<div class="lb-trans">如果大型科技公司面臨的逆風持續惡化，市場廣度的增加和對大型股的輪動可能會持續。我們知道，極端市場集中後的時期歷史上與標普 500 等權重指數的超額表現相吻合，市場參與者理解該策略相對錶現的來源和驅動因素可能是有益的。
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<div class="lb-trans"><hr/>
</div>1 The Wall Street Journal, “Small Stocks Finish Week at Records,” Jan. 16, 2026.
<div class="lb-trans">1《華爾街日報》，“小型股票創下週記錄”，2026 年 1 月 16 日。
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<div class="lb-trans"><hr/>
</div>More By This Author:
<div class="lb-trans">更多來自此作者的文章：
</div>Fashionably Late Cycle: The S&amp;P 500 Market Leaders Index
<div class="lb-trans">時尚的晚週期：標普 500 市場領袖指數
</div>All That Glitters Isn’t Just Gold: 2025 Thematic Performance In Review
<div class="lb-trans">閃閃發光的不僅僅是黃金：2025 年主題表現回顧
</div>Houston, We Have An Index: Exploring the S&amp;P Kensho Global Space Index
<div class="lb-trans">休斯頓，我們有一個指數：探索標普 Kensho 全球太空指數
</div>

Big Tech, Breadth And Balance

- 美國股市近期波動，受大科技企業財報影響，標普 500 指數先揚後抑。  
- 小型股表現優於大盤股，標普小型股 600 自 2026 年伊始已超出 4%。  
- 市場參與度擴大，平衡加權指數預計將在繼續的市場寬鬆中表現突出。

大型科技公司、市場廣度與平衡