Since the beginning of this year, the US stock market has repeatedly hit new highs. Star strategist Michael Hartnett has made another bold prediction, stating that the end of this bull market is far from over.
Recently, in the latest &#34;Flow Show&#34; report, Michael Hartnett, Chief Investment Strategist at Bank of America, predicted that the S&amp;P 500 index will reach a historic high of 9,914 points in September 2027.
This seemingly crazy prediction is not unfounded, but is based on the cold statistics of US stock market bull markets over the past century: the average gain of 14 bull markets was 177%, with an average duration of 59 months. According to this historical script, we are in the midst of an epic bubble, and the end is far from near.
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Hartnett stated that this astonishing long-term prediction is derived from his &#34;lucky number&#34; model based on themes such as productivity, valuation, and AI.
<ul>
<li>32: In 26 out of 32 elections in 2024, voters removed the &#34;incumbents&#34;; so far in 2025, voters have removed the &#34;incumbents&#34; in 6 out of 11 elections.</li>
<li>49%: The share of votes won by mainstream German parties in the February 2025 election, the lowest since 1945 (the lowest for UK mainstream votes since 1918, and for France since 1945).</li>
<li>65 million: Generation Z and millennial voters exceed 50 million baby boomers, becoming the majority voting group in the 2024 US election.</li>
<li>196: The number of executive orders by President Trump in 2025, second only to Roosevelt's during 1933-37 in US history.</li>
<li>6.1 times: The ratio of financial asset prices to US GDP, slightly below the historical peak of 6.3 times in Q2 2021. This indicates that the inflation of financial markets has far outstripped the support of the real economy.</li>
<li>1641: Since the 2008 global financial crisis, central banks have cut interest rates 91 times in 2025, the fastest easing cycle since 2020.</li>
<li>2259 years: If you spend $100 every second, it would take 2259 years to match the $7.1 trillion spent by the US government in the past year.</li>
<li>$37 trillion: US government debt (a historical high), exceeding the total GDP of China, Japan, Germany, and India.</li>
<li>1905: The last year the Italian government had a budget surplus (France in 1974, the UK in 2001, and the US in 2001).</li>
<li>3.25%: The yield on 5-year US Treasury bonds ($1.2 trillion) remains below this yield.</li>
<li>52%: The nominal GDP growth rate of the US economy over the past 5 years (inflation = 28 percentage points, growth = 24 percentage points), the fastest expansion since the stagflation of the 1970s</li>
<li>1.3%: The labor productivity growth rate in the United States over the past four quarters is 1.8%, while it was 1.8% in the 2020s, 1.2% in the 2010s, 2.7% in the 2000s, and 2.2% in the 1990s.</li>
<li>-1.3%: As of January 25, the 10-year rolling return on U.S. Treasury bonds has recorded a loss... similar to the &#34;buying humiliation&#34; inflection point of U.S. stocks in February 2009 (when the rolling return was -3.4%, the worst since 1939) and commodities in June 2018 (when it was -7.7%, the worst since 1933).</li>
<li>$7.2 trillion: The asset management scale of U.S. money market funds, a record level of &#34;watching cash.&#34;</li>
<li>9914: History indicates that the S&amp;P 500 index peaked at 9914 in September 2027... Over the past 100 years, the average increase of 14 U.S. stock bull markets has been 177% over 59 months.</li>
<li>5.3 times: The price-to-book ratio of the S&amp;P 500 index is currently at its highest level since 1946, with only 2% of price-to-earnings ratios exceeding 125 times in the past 27.4 years.</li>
<li>4403: The number of ETFs listed in the U.S. has now surpassed the number of U.S. stocks (4142 listed on NASDAQ).</li>
<li>63%: The percentage of the market value of U.S. railroads in the total U.S. stock market in 1881 (other new paradigm concentrations peaked... Nifty 72 accounted for 40% of SPX, Japan accounted for 45% of ACWI in 1989, and 40% of SPX in 2000... 'AI Big 10'1 = 39% of today's U.S. stock market).</li>
<li>8.1%: The average unemployment rate for U.S. graduates over the past three months, soaring from 4.0% in December 2024 to the highest level since July 2021.</li>
<li>2x: By 2030, artificial intelligence will double the global data center electricity demand (equivalent to Japan's total electricity consumption)... U.S. electricity prices have risen by 6.3% over the past 12 months.</li>
<li>55%: The percentage of capital expenditure in the operating cash flow of the &#34;Mag 7,&#34; up from 20% in 2012.</li>
<li>40%: The proportion of consumption in China's GDP will rebalance higher... compared to Germany (50%), Japan (55%), France (58%), the UK (61%), and the U.S. (68%).</li>
<li>71%: Despite a significant increase in stock prices by 330% over the past five years, Japanese bank stocks are still 71% lower than their historical peak in 1987.</li>
<li>1975: The last year the U.S. had a trade surplus... The current effective tariff rate on imported goods in the U.S. is 15%, the highest level since 1937.</li>
<li>33%: The average decline of the U.S. dollar from peak to trough in the last five bear markets since 1967 (the dollar has fallen -11% since the peak on January 25).</li>
<li>0.3%: According to Bank of America's July global fund manager survey, the average allocation of cryptocurrency as a percentage of assets under management (the same survey shows gold = 2.2% of average institutional assets under management)</li>
</ul>
<h2>&#34;Frenzied&#34; Valuation and the Shadow of the &#34;AI Bubble&#34;</h2>
On the frenzied road to 9,914 points, Hartnett also pointed out the potential risks in the current global capital markets.
According to this &#34;lucky number&#34; model, the price-to-book ratio of the S&amp;P 500 index has reached 5.3 times, the highest level since the end of World War II in 1946. Its trailing price-to-earnings ratio has also reached 27.4 times, an extreme figure that has only been surpassed 2% of the time in the past 125 years. By any traditional standard, the market is extremely expensive.
The core driving force behind this valuation frenzy is undoubtedly AI.
Data from the report shows that the market capitalization concentration of the &#34;AI Ten Giants&#34; has reached 39% of the total market capitalization of U.S. stocks. This is strikingly similar to historical bubble peaks, such as the &#34;Nifty Fifty&#34; accounting for 40% of the S&amp;P in 1972, the Japanese stock market accounting for 45% of the global market in 1989, and technology stocks accounting for 40% of the S&amp;P in 2000.
At the same time, the capital expenditure of the &#34;Mag 7&#34; has surged from 20% of its operating cash flow in 2012 to 55%. AI is expected to double the power demand of global data centers by 2030, equivalent to the entire electricity consumption of Japan.
<h2>The &#34;Quiet&#34; Rise of the Chinese Market</h2>
While all eyes are focused on the United States, Hartnett keenly pointed out the structural changes in global capital flows, which may be the true &#34;expectation gap.&#34;
Despite low media attention, Hartnett noted that the Chinese stock market has been the best-performing market globally over the past two years. Unlike the historical highs of U.S., European, and Japanese stocks relative to bonds, Chinese stocks remain low relative to domestic bonds. In the latest week, a staggering $3.9 billion flowed into Chinese stocks, the highest since April 2025.
Meanwhile, U.S. Treasuries are experiencing historic &#34;humiliation.&#34; As of January 2025, the rolling return on ten-year U.S. Treasuries was -1.3%, setting a record for historical losses. Hartnett believes this creates a classic &#34;buying distressed assets&#34; contrarian investment entry point, similar to the U.S. stock market in February 2009 and commodities in June 2018.
As global rebalancing progresses, the U.S. dollar also seems to have entered a downward channel. Since the peak in January 2025, the dollar index has fallen by 11%. Historically, the average decline in the five dollar bear markets since 1967 has reached 33%.

.SPX

Over the past 100 years, the average increase of 14 bull markets in the U.S. stock market has been 177%, with an average duration of 59 months. According to this historical script, we are in the midst of an epic bubble, and the end is far from over

- Michael Hartnett, chief investment strategist at Bank of America, predicts the S&P 500 index will reach 9,914 by September 2027, based on historical bull market statistics.  
- He highlights that the current market's price-to-book ratio of 5.3 is the highest since 1946, driven largely by AI's influence, with the "AI Big 10" accounting for 39% of total market capitalization.  
- Hartnett also notes a structural shift in global capital flows, with significant investments moving into the Chinese stock market, contrasting with the historical losses in U.S. Treasury yields.

The most accurate analyst in the US stock market, Hartnett: The S&P 500 will reach a historical peak of 9,914 points in September 2027