这篇文章认为，长期延续的美国牛市一直受到公开股票供给缩减的支撑，作者把这种现象称为去股权化（de-equitisation）。自2003年以来，当时标普500指数较网际网路泡沫后的高点下跌了50%，10年期美国国债收益率为3%，疲弱的风险偏好、股票回购、杠杆收购以及私募股权退市交易，都使股权发行保持低迷。Datastream的数据显示，在过去4年中，美国和英国的公开股票市场都在某种程度上出现了去股权化，而这一模式与1998-2000年形成鲜明对比，当时美国IT产业将其股权基础扩大了40%。

如今的证据显示，随著AI热潮让大型科技公司变得更资本密集，情势正在转变。Magnificent 7在2025年回购了2300亿美元股票，这有助于为员工股票计划提供资金，甚至为科技业其他公司的IPO提供资金，但这种自我融资模式正在改变。Alphabet、Amazon、Meta和Microsoft预计今年将投资7250亿美元，而Meta和Alphabet在2024年向市场返还920亿美元后已暂停回购。Apple仍在回购股票，并已批准在2026年再回购1000亿美元，尽管在4.3万亿美元市值下，其影响较小。与此同时，据说OpenAI和Anthropic在2026年已私下筹得1520亿美元，显示最大的股权创造正移向公开市场之外。

文章警告说，这种私人市场的股权化可能很快会透过SpaceX、OpenAI和Anthropic潜在的IPO溢出到上市市场，三者合计估值可能高达4万亿美元。这一金额意味著美国公开股票市场大约扩张6%，与1990年代末泡沫相似，而早期投资者和员工持有但未出售的股票可能在未来数年持续压制市场。如果回购放缓、私有化交易减少，那么一直帮助股票在高估值、利率上升、贸易战和地缘政治紧张中站稳脚跟的去股权化「看跌期权」可能会减弱，使价格更容易受到供给影响。

This article argues that the long-running US bull market has been supported by a shrinking supply of public equity, a pattern the author calls de-equitisation. Since 2003, when the S&P 500 had fallen 50% from its post-dotcom peak and 10-year US Treasury yields were 3%, weak risk appetite, buybacks, leveraged takeovers, and private equity delistings kept equity issuance subdued. Datastream data show that both the US and UK public equity markets have de-equitised to some extent in each of the past 4 years, and the pattern contrasts sharply with 1998-2000, when the US IT sector expanded its equity base by 40%.

The evidence now points to a shift as the AI boom makes Big Tech more capital intensive. The Magnificent 7 bought back $230bn of shares in 2025, helping finance employee stock plans and even providing funding for IPOs elsewhere in tech, but this self-financing model is changing. Alphabet, Amazon, Meta, and Microsoft are expected to invest $725bn this year, and Meta and Alphabet have paused buybacks after returning $92bn to the market in 2024. Apple is still buying back shares, with another $100bn authorized for 2026, though the effect is smaller at a $4.3tn market cap. Meanwhile, OpenAI and Anthropic are said to have raised $152bn privately in 2026, signaling that the biggest equity creation is moving outside public markets.

The article warns that this private-market equitisation may soon spill into listed markets through potential IPOs from SpaceX, OpenAI, and Anthropic, which could seek a combined valuation of up to $4tn. That amount would imply about a 6% expansion of the US public equity market, similar to the late 1990s bubble, while unsold stock from early investors and employees could overhang markets for years. If buybacks slow and take-private deals fade, the de-equitisation “put” that has helped equities withstand high valuations, rising rates, trade wars, and geopolitical tension may weaken, leaving prices more exposed to supply.