这篇文章主张，美国牛市是由股票供给收缩所支撑，而不是由股票发行正常激增所推动。自2003年以来，当时标普500指数已较 dotcom 泡沫后高点下跌50%，而10年期美国国债殖利率约为3%，投资人一直避免拉近股票与债券之间的估值差距，让股票回购、债务融资收购、私募股权退市以及疲弱的IPO活动，共同推动作者所称的去股权化。Datastream 数据显示，在过去4年中，美国和英国的公开股票市场每一年都出现去股权化。

这种模式在美国科技业尤其明显。在1998-2000年的科技热潮中，美国IT部门的股权基础扩大了40%，但在过去4年里却缩小了4%。作者表示，这一轮科技周期之所以能自我融资，是因为美国大型IT公司不需要外部资本，而是透过回购把现金返还出去。Magnificent 7 在2025年回购了2300亿美元的股票，其中一部分支持了员工持股计划，另一部分则间接为该产业其他地方的IPO提供了资金。

该文章指出，AI 热潮可能正在结束去股权化阶段，因为主要平台正从轻资本支出模式转向重度投资。Alphabet、Amazon、Meta 和 Microsoft 预计今年将合计投资 725bn，随著它们加速投入 AI，这一水准更让人联想到早期那些资本密集型繁荣，如运河、铁路、无线电和电信。其含意是，如果这些公司需要外部融资，或如果库藏股回购失去抵销发行的能力，股票供给可能会再次开始上升，不过文章对这种转变会有多大或能持续多久仍未定论。

This article argues that the US bull market has been supported by shrinking equity supply rather than a normal surge in share issuance. Since 2003, when the S&P 500 had fallen 50% from post-dotcom highs and 10-year US Treasury yields were about 3%, investors had avoided closing the valuation gap between stocks and bonds, allowing buybacks, debt-financed takeovers, private-equity delistings, and weak IPO activity to drive what the author calls de-equitisation. Datastream data suggest both US and UK public equity markets have de-equitised in each of the past 4 years.

The pattern has been especially clear in US technology. In the 1998-2000 tech boom, the US IT sector expanded its equity base by 40%, but over the past 4 years it has shrunk by 4%. The author says this latest tech cycle has been self-financed because large-cap US IT firms have not needed external capital and have instead returned cash through buybacks. The Magnificent 7 bought back $230bn of shares in 2025, some of which supported employee share plans and some of which indirectly financed IPOs elsewhere in the sector.

The article suggests the AI boom may be ending the de-equitisation phase because major platforms are shifting from capex-lite models to heavy investment. Alphabet, Amazon, Meta, and Microsoft are expected to collectively invest $725bn this year as they push into AI, a level more reminiscent of earlier capital-intensive booms such as canals, railways, radio, and telecoms. The implication is that equity supply could start rising again if these firms need external financing or if buybacks lose their ability to offset issuance, although the article leaves open how large or durable that shift will be.