在瘋狂股市中生存:對話『Just Keep Buying』作者 Nick Maggiulli,重構投資底層邏輯 一口新飯 2026-05-18

策略性臨在:AI 範式轉移與市場擇時的代價

在當前由 AI 驅動的狂熱市場中,投資者最常問的問題是:“我現在還能買嗎?”《持續買進》(Just Keep Buying)的作者 Nick Maggiulli 指出,投資决策的核心在於時間框架(Time Frame)。如果你在未來 5 年內需要這筆錢,當前的市場估值確實令人不安;但如果是為了 20 到 30 年後的退休生活,市場總會以你意想不到的方式帶來驚喜。

Maggiulli 承認,自己在一年前曾因 AI 估值過高而轉向看空,甚至將退休賬戶的股票比例從 100% 下調至 80%,但他很快意識到自己錯了。AI 不僅僅是泡沫,它代表了一種範式轉移(Paradigm Shift)。儘管歷史上重大技術變革初期總伴隨著過度投資,但對於使用過 ChatGPT 或 Claude 的人來說,其提升效率的潛力是實實在在的。雖然目前的經濟模型尚未完全顯現,但隨著計算成本的持續下降,AI 終將展現其超越人類成本效益的價值。

Original English Source

In this market, can a normal investor like me just keep buying? It depends on your time frame. That's everything. Like if if you need the money in the next 5 years, no. I would say absolutely not. You should not be buying right now. If you're this is a retirement account for 20 30 years in the future, I would say yes cuz the market will surprise you in many ways. A year ago I was bearish. I'm now bullish once again over the last year because AI was seemed so crazy. I got a little bearish for the first time ever and I reduced my stock exposure by you know 20%. I went from a 100% stocks in my retirement account to 8020 which to me that's like being bearish and at this point now I'm like why am why why did I do that? It's probably a bit of both, right? If you look at the history of any large technological change, there's always a ton of players that rush in. There's a lot of capital that goes in. There's always overinvestment. And I guarantee in this case there's going to be some overinvestment. At the same time, it is a paradigm shift for a lot of things. Anyone that's used, you know, Chat GBT, Claude, you know, Perplexi, you name it, you've seen things like, wow, this can save me time.

估值迷霧:為什麼市銷率(P/S)比市盈率(P/E)更可靠

在分析 Nvidia 等科技巨頭時,Maggiulli 更傾向於使用 市銷率(Price-over-Sales: 公司市值與營收的比率)而非傳統的市盈率。他指出,利潤(Earnings)極易受到各種會計手段的操縱,而銷售額(Sales)則難以造假。他曾將 Nvidia 當前的市銷率與 1999 年時的 Microsoft 進行疊加,發現兩者驚人地吻合,這曾讓他感到恐懼。

然而,AI 公司的增長速度打破了歷史常規。以 Anthropic 為例,其年度經常性收入(ARR)在一年內從 30 億美元暴增至 45 億美元,這種規模的指數級增長在傳統經濟學中幾乎無法想象。這種瘋狂的增長數據解釋了為何市場願意給出如此高的溢價。當前的市場博弈在於:這種增長是否具備持續性?這正是看多與看空陣營辯論的核心。

Original English Source

Price over sales. It it just there were too many things that just reminded me of 2021 and I think I got a little bit of deja vu. I overlaid the Nvidia price to sales with the Microsoft price to sales in 99 and like the the they matched. Price to sales I like that metric more than earnings because earnings can be manipulated with all sorts of accounting tricks. Sales is like that's what you have. Like you have the price of your company and you have your revenue. can't to fake sales is like straight up fraud and people very rarely do that. So for me, I was looking at these data series and I was like this is like seems crazier than the dot bubble and I think it there's just a lot of growth and that maybe justified it because a lot of that growth has happened. I mean look at what happened with Anthropic. I think I think I just read like they were 3 billion AR now they're 45 billion AR in a year. Like that is absurd growth.

持續買進的核心:多元化收益資產的三大支柱

Maggiulli 在其著作《持續買進》中提出的核心公式是:持續買入多元化的收益資產(The continual purchase of a diverse set of income-producing assets)。這個理念由三大支柱構成:

  1. 持續買入(Continual Purchase):通過時間攤平風險,數據證明即使你能預知未來,按月定投依然是普通人的最優選擇。
  2. 多元化(Diverse Set):分散投資是信心的來源。單一市場(如日股或台股)可能陷入長期低迷,但全球市場的組合能提供更穩定的回報。
  3. 收益資產(Income-producing Assets):指股票、固定收益產品和房地產等能產生現金流的資產,而不包括黃金或比特幣(儘管他建議將後者作為 2%-5% 的對沖配置)。

他強調,長期投資的信念並非來自對單一國家的盲目樂觀,而是基於工業革命以來的技術進步趨勢。歷史數據顯示,發達國家的股票市場長期回報通常高於短期國債(T-bills)約 4%。只要人類社會仍在創造價值和技術創新,這個趨勢就不會停止。

Original English Source

The mantra of the book is... the continual purchase of a diverse set of income-producing assets. There's three pillars to that. Continual purchase. You're buying over time. Diversification is at the heart of this. And then of income producing assets... anything that can produce some sort of income. That includes equities, that includes fixed income, that includes real estate. That does not include things like gold, Bitcoin, etc. Does that mean you shouldn't own those? No. But I don't think they should be the vast majority of your portfolio. The conviction doesn't just come from like okay, we have one country with a you know a century of return. It comes from diversification. Since at least, you know, the 1800s, since the industrial revolution, we've been producing, humans as a whole have been producing more and more... and I don't think that trend is going to stop. And so that's where the conviction comes from.

心理博弈:克服『等待回調』與『抄底』的偏誤

許多投資者迷戀於“逢低買入”(Buy the Dip),但 Maggiulli 用數據無情地打破了這一幻想。他舉例說,一個在 2017 年等待大回調的人,直到 2020 年新冠疫情爆發才等到 33% 的跌幅,即便他精準地在 2020 年 3 月 23 日的最低點抄底,他買入的價格依然高於 2017 年初的價格。等待的機會成本往往遠超回調帶來的利差。

此外,他指出“抄底”可能演變為致命的財務毀滅。1929 年大崩盤後,市場在 1931 年已經腰斬,許多人認為是“世紀買點”並全倉殺入,結果市場在隨後的一年內又跌了 60%。這就是行為偏誤(Behavioral Biases)的威力。為了對抗自己的偏誤(如他因經歷 2008 年金融危機而對房產抱有偏見),他採用了“微調”策略:在感到恐懼時,僅將持倉比例從 100% 降至 80%,而不是全盤退出。這能讓你既能“晚上睡得著”,又不至於錯過市場的長期漲幅。

Original English Source

The issue is... if you wait for a dip, a lot of times when that dip finally comes, it's going to be even higher. I remember back in 2017, there was an investor... he waited, waited, waited. Finally, COVID happens 2020. Even if he perfectly knew the bottom and bought on March 23rd, 2020, he still would have bought at a higher price than if he had bought back in early 2017. The worst dip in, you know, US market history was the Great Depression. The market was already down, I think, like 50%. From 1931 to the summer of 1932, the market went down 60%. This is after it already had two years of just getting destroyed. So you keep talking about buying the dip, but at some point you may face a dip where it just keeps dipping. That is truly destructive like nothing else.

財富階梯:為什麼職業生涯比選股更重要

對於年輕投資者,Maggiulli 給出了一個令人驚訝的建議:忘記股市,專注於你的職業收入。他提出了一個觀點:儲蓄是為了窮人,投資是為了富人(Savings is for the poor and investments is for the wealthy)。當你只有 1000 美元時,10% 的回報僅有 100 美元,不如去多打一份工或提升職業技能;而當你擁有 100 萬美元時,同樣的 10% 回報能抵得上普通人一年的工資,這時選股研究才有意義。

數據顯示,財富與收入高度正相關。高收入者不僅存得多,更有能力承擔風險。他告誡投資者不要被社交媒體上那些“買入 Nvidia 賺了百萬倍”的故事所誘惑,那往往是火雞問題(Turkey Problem: 平時看似安穩、自信不斷積累,最後一天卻被斬首):那些通過高槓桿或激進策略獲勝的人,如果不收手,最終往往會因為一次不可預見的市場意外而清空利潤。真正的投資成功在於生存(Survival),即確保你能長期留在遊戲中,直到達成生活目標。

Original English Source

Savings is for the poor and investments is for the wealthy. If you have a thousand bucks and you get a 10% return that's $100... but if you have a million dollar portfolio you get a 10% return that's $100,000. The stock research and beating the market only makes sense once you have a ton of money. Focus on your career. The data overwhelmingly supports a model where people are saving over time and putting it into the market. It's their careers. Taleb has this thing called the turkey problem... the confidence of the turkey goes up and then it just falls like that. That's what selling call options is like. You get more comments. Oh my god, I'm right. I'm a genius. And then one day you have this market event you couldn't have foreseen and then you lose everything. The only version of success I care about is whether you survive.

現實主義投資:現金配置與債券的持續價值

在資產配置上,Maggiulli 展現了實用主義的一面。雖然他推崇全額投資,但他目前持有約 35% 的固定收益資產(如短期國債 T-bills),原因並非看空市場,而是因為他計劃買房。他強調,投資的目的是為了未來的消費,為了生活目標(如結婚、生子、買房)而保留現金是理性的選擇,這與“試圖擇時抄底而持有現金”有本質區別。

對於債券,他強烈建議保持短久期(Short Duration: 5年以內)。2022 年 60/40 組合經歷了史上最差的一年,正是因為長久期債券在加息週期中遭遇了毀滅性打擊。最後,他提醒散戶投資者,當前的最大錯誤往往是過度集中風險。許多人認為持有 Nvidia、微軟和蘋果就是多元化,但實際上這依然是極度集中的科技股頭寸。真正的多元化需要跨越行業、跨越地域,甚至跨越資產類別。

Original English Source

The reason I'm holding cash is because I'm trying to buy a house. My cash pile is going up because I have a legit reason... if we include those assets in my portfolio my allocation would be more like 35% bonds and 65% stocks. I personally recommend short-term bonds, anything with a duration of less than 5 years. Anyone that bought long-dated bonds got destroyed because as you know when rates go up prices go down. My guess is people are probably taking too much risk right now. Too much undiversified risk. You can own Nvidia and Microsoft and Apple and you're like, 'Oh, look. I'm diversified,' but you really are pretty concentrated in tech.

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关键字: dollar-cost-averaging asset-allocation behavioral-finance index-fund-investing market-psychology