The S&P 500 fell 1.36% on Fed Chair Powell’s penultimate FOMC day on Wednesday (3/18/26).  While a hallmark of Powell’s tenure as Chair has been the stock market’s tendency to trade sharply lower in afternoon trading on Fed Days, the market has also done very well over the entirety of his 8+ year term.

When Powell became Fed Chair in February 2018, the combined market cap of stocks in the S&P 500 was $23.5 trillion.  That number has ballooned by $35.4 trillion up to $58.9 trillion today.

The S&P 500 has gained more than 180% since 2/5/18 when Powell became Chair, representing an annualized total return of 13.7%.  The tech-heavy Nasdaq 100 has gained much more at 300.9% (18.7% ann.), while the Dow 30 is up 123%.

Compared to the rest of the world, Powell has kept US markets in a dominant position.  The S&P has beaten the rest of the world by more than 100 percentage points since his time as Chair began.

Looking at sector performance, Technology has more than doubled the next-best sector (Communication Services) during Powell’s tenure.  As shown above, Tech has returned 418% since Powell took over, while Materials and Real Estate are the only two sectors that haven’t at least doubled.

Of the current S&P 500 members that were trading back in early 2018 when Powell became Chair, 59% have gained at least 100% since then.  There are nearly just as many S&P 500 stocks up 500%+ (39) since Powell’s tenure began as there are stocks that are down (45).

Below is a table showing the best-performing S&P 500 stocks since Powell became Chair, with the seventeen “10-baggers” highlighted in green.

You may have thought NVIDIA (NVDA) would be at the top of this list given its place as the largest company in the world right now, but a company that’s just over a tenth of NVDA’s size actually has it beat.  Comfort Systems (FIX) — which builds out the mechanical, electrical, and plumbing systems for AI data centers and other infrastructure projects — is actually #1 when it comes to share-price performance under Powell.  As shown, FIX is up 3,555% compared to a gain of 3,314% for NVDA.

Most of the names on the list of big winners since Powell became Chair are directly related to the AI Boom, but some that are not include Axon Enterprises (AXON) — which sells Tasers and police bodycam hardware and software, Carvana (CVNA) — which sells used cars, and Eli Lilly (LLY) — which sells weight-loss drugs and other pharmaceuticals.

Sign up for Bespoke’s Think BIG mailing list to receive an interesting market stat like this in your inbox a few times per week.  Click here or on the image below to sign up.  An email is all we need!

While there are seventeen “10-baggers” since Powell became Chair, not all of those stocks are in uptrends right now.  Below are price charts for the six best performers in our table above.  While Ciena (CIEN) and Comfort Systems (FIX) remain in strong uptrends, the other four have either traded sideways or lower over the last six months.

Of the six biggest winners under Powell, Ciena (CIEN) is the only one trading at record highs today.  Its price action lately has been a sight to behold.

Last year at the tariff-tantrum lows, the stock was trading in the low-$50s.  It’s currently trading above $400.

Ciena (CIEN) somewhat slid under the radar in the early years of the AI Boom, but over the last year or so, investors haven’t been able to get enough of it.

That’s because Ciena makes some of the most important networking gear for AI data centers (shown below).  Every time a company makes a bigger, smarter LLM for consumption, they need more of Ciena’s gear to make that data work and move faster.

What’s even crazier about Ciena (CIEN) is that even though the stock is up nearly 1,000% in the last few years and 1,700% since Powell became Fed Chair, it still hasn’t gotten back to half of what it peaked at during the Dot Com Bubble of the late 1990s.

Just as Ciena is a key player in the AI infrastructure build-out right now, it was also a key player in the Internet/Telecom buildout of the late 1990s.  After rallying from $30 to north of $1,000/share at its peak, shares plummeted to as low as $5 after the bubble burst in the early 2000s.

This should be a key reminder of how carried away investors can get during market manias, but it also shows that while the AI Boom indeed has a lot of hype, things were even crazier back in the late 90s.

So far we’ve only discussed winners since Powell became Fed Chair, but below is a list of the S&P 500 stocks that have done the worst over his tenure.  The names shown are the 23 stocks down at least 30% since 2/5/18, led by Baxter International (BAX) with a 70% drop.

Two cruise-lines rank 2nd and 3rd worst (Norwegian and Carnival) with declines of more than 60%, and another three stocks have been more than cut in half: Viatris (VTRS), Kraft Heinz (KHC), and PG&E (PCG).  Other well-known names on this list of losers include Biogen (BIIB), PayPal (PYPL), Campbell’s (CPB), Boeing (BA), Molson Coors (TAP), and Wynn Resorts (WYNN).

Like this analysis?  Become a Bespoke Premium member today using our March Madness special!  Click below for details on how to sign up:

As if news headlines and price action haven’t been signals enough, investor sentiment readings are also pointing toward negative outlooks in the wake of the conflict in the Middle East. The American Association of Individual Investors (AAII) weekly sentiment survey saw only 30.4% of respondents report bullish sentiment this week. That is the lowest level since the week of 9/11/25, when it registered 28%.  Additionally, as we first highlighted in today’s Morning Lineup, the 1.5 percentage point drop this week marked the seventh consecutive weekly decline in bullish sentiment, which ties another 7-week-long streak from May 1993.

Given the drop in bulls, bearish sentiment has continued to surge. This week, the reading rose another 5.6 percentage points to 52%. That is the highest reading since last May, when it was at 59.3%.  Throughout the survey’s history since 1987, less than 5% of weekly readings have seen more than half of respondents report as bearish.

With inverse moves in bulls and bears, the bull-bear spread fell to -21.6.  That narrowly surpasses the previous local low of -21.5 from the week of 9/11/25, registering the worst reading since last May.

We would also note that not only has there been a big move toward bearish sentiment due to lost bullishness, but a big drop in those reporting neutral sentiment has also been a factor.   Only two weeks ago, 31.4% of respondents reported neutral sentiment for the highest reading since January 2025.  In the two weeks since then, it has fallen to 17.%, which ranks in the 4th percentile of all periods on record, and is the lowest since a reading of 16% last September.

In other words, sentiment has turned overwhelmingly bearish. That is also reflected in other surveys like the Investors’ Intelligence and NAAIM Exposure index readings.  The latter now indicates the lowest level of long exposure to equities since last spring, and that reading is now also below the historical average. The Investors’ Intelligence survey is still marginally bullish relative to historical norms, although it too is quickly approaching bearish readings.

Like this analysis?  Join our premium members by starting a trial today!  Click below for details on how to sign up: