Research & Evidence

The question has a popular answer and an academic answer. They are not the same.

Headlines say Nancy Pelosi beat every hedge fund on Wall Street. Peer-reviewed research says the picture is more contested. Two of the most cited academic papers reach opposite conclusions. An exchange-traded fund that copies congressional trades has returned roughly what the S&P 500 has returned. Here is what the actual evidence says about whether members of Congress beat the market, and why the honest answer is narrower than the popular one.

+85 bps

per month: the excess return senators earned on their stock purchases between 1993 and 1998, per the Ziobrowski 2004 study, the foundational paper that launched the entire "Congress beats the market" debate

-2 to -3%

annual underperformance found by Eggers and Hainmueller in 2013 using 2004 to 2008 data, the peer-reviewed paper that directly challenged Ziobrowski and found congressional portfolios to be mediocre at best

Feb 2023

the launch of the NANC and KRUZ exchange-traded funds, which copy Democratic and Republican congressional trades respectively, providing the cleanest real-world test of whether the outperformance thesis survives a passive fund structure

1 of 535

the share of Congress typically represented in "top performer" headlines: the median member holds boring index funds, does not actively trade, and does not show up in the return rankings at all

Why the question is harder than it looks

"Do members of Congress beat the market" sounds like a clean empirical question. Collect the trades, compute the returns, compare to a benchmark, publish the answer. The problem is that every step of that sentence is contested.

Collect the trades: congressional disclosures report amounts in brackets, not exact values. A filing showing a trade between $100,001 and $250,000 could be $101,000 or $249,000. Analysts typically use the midpoint, which means every computed return is an estimate built on a 2.5x range assumption. Compute the returns: disclosures give transaction dates, not execution prices. The closing price on the disclosed date is a proxy, not ground truth. Compare to a benchmark: the S&P 500 is the popular choice, but a factor-matched benchmark that controls for size, book-to-market, and momentum gives very different results, which is part of why the academic literature has reached different conclusions from the same raw data.

Then there is the question of whose returns we are even measuring. Nancy Pelosi is the reporter. Paul Pelosi is the trader. Ritu Khanna's family trusts run the trading for the Khanna household, with Ro Khanna publicly stating he does not direct the trades. Linda Mays McCaul's accounts are managed by a third-party firm. Treating every disclosure as "Congressman X's return" erases the structural reality that the active traders are often spouses, trusts, and professional managers who are simply reportable because the member is in Congress.

The honest answer to "do members of Congress beat the market" depends on three narrower questions: which members, over what period, using what benchmark. Different answers to those three questions are what produces the gap between the popular narrative and the academic one.

Four peer-reviewed papers that shape the evidence

The academic literature on congressional trading returns is smaller than the media coverage suggests, but four studies do most of the intellectual work. Read together, they tell a more nuanced story than any single one tells alone.

1

Ziobrowski, Cheng, Boyd, and Ziobrowski (2004): the paper that started the field

"Abnormal Returns From the Common Stock Investments of the U.S. Senate," Journal of Financial and Quantitative Analysis, Vol. 39, No. 4

Using roughly 6,000 common stock transactions disclosed by U.S. senators between 1993 and 1998, the authors found that stocks purchased by senators outperformed a characteristic-matched benchmark by approximately 85 basis points per month, which annualizes to something in the range of 10 to 12 percent per year above the market. Stocks that senators sold underperformed the market in the months after the sale, which is the pattern you would expect if the sellers were acting on informed judgment about future price declines.

The paper's methodology used the characteristic-based matching approach developed by Daniel, Grinblatt, Titman, and Wermers in 1997, which controls for size, book-to-market ratio, and prior-year momentum. The authors explicitly invited the interpretation that senators were benefiting from information advantages tied to their roles, setting up what would become known as the "political intelligence" debate and directly influencing the congressional deliberations that produced the STOCK Act eight years later.

2

Ziobrowski, Boyd, Cheng, and Ziobrowski (2011): the House follow-up

"Abnormal Returns From the Common Stock Investments of Members of the U.S. House of Representatives," Business and Politics, Vol. 13, No. 1

The same authors repeated the study for the House of Representatives, using a larger sample of approximately 16,000 transactions covering 1985 to 2001. They found that representatives' stock purchases outperformed by approximately 55 basis points per month, which annualizes to roughly 6 to 7 percent per year, substantially less than the Senate figure but still positive and statistically significant.

The authors interpreted the weaker House result as consistent with senators having greater access to market-moving information: senators serve longer terms, sit in a smaller chamber, and tend to concentrate on fewer committees with deeper jurisdiction. The House paper landed during active congressional debate on trading reform and was cited repeatedly in the 2011 hearings that produced the STOCK Act the following year.

3

Eggers and Hainmueller (2013): the paper that pushed back

"Capitol Losses: The Mediocre Performance of Congressional Stock Portfolios," Journal of Politics, Vol. 75, No. 2

Andrew Eggers and Jens Hainmueller reexamined congressional trading performance using data from 2004 to 2008 and reached the opposite conclusion. In their sample, congressional portfolios underperformed the market by approximately 2 to 3 percent per year. Their paper is titled "Capitol Losses" precisely because the finding was the reverse of the Ziobrowski narrative.

The authors identified several methodological concerns with the earlier Ziobrowski work: sensitivity to the specific sample window, which covered the late-1990s tech boom; benchmarking choices that may not have fully captured factor exposures; and inadequate modeling of transaction costs. Their conclusion was that members of Congress, in aggregate, trade more like moderately wealthy retail investors than like privileged insiders. A rigorous account of this field has to reckon with Eggers and Hainmueller as seriously as it reckons with Ziobrowski. The popular narrative tends to cite one and ignore the other.

4

Karadaş (2019): the cleanest research design

"Trading on Private Information: Evidence from Members of Congress," published in Financial Review

Serkan Karadaş took a narrower but more rigorous approach: rather than asking whether Congress beats the market in aggregate, he asked whether members outperform specifically on stocks relevant to their committee assignments. The answer was yes. Trades that aligned with committee jurisdiction showed modest but statistically significant outperformance. Trades outside that alignment did not.

Karadaş's result is the most defensible claim in the entire literature. It does not say "Congress beats the market." It says something more precise: when a member of Congress trades a stock whose regulation, contracting, or oversight they are actively involved in, the trade tends to work better than a comparable trade by someone without that involvement. That narrower claim is what our own committee conflict analysis documents at the individual-trade level, and it is the claim that makes sector-specific tracking worth the effort.

What the recent data actually shows: 2020 through 2025

The peer-reviewed literature is thin after 2019. Most of the public analysis since then has come from industry reports, most notably the annual congressional trading reviews published by Unusual Whales and by Quiver Quantitative, along with periodic investigations in the New York Times, the Washington Post, Business Insider, and Bloomberg.

These industry reports have produced consistent top-performer rankings. Nancy Pelosi and Paul Pelosi top the Democratic side in most years. Josh Gottheimer, Ro Khanna (through his family's trusts), and a rotating set of others appear in the upper quartile. On the Republican side, Mark Green, Kevin Hern, Tommy Tuberville, and Markwayne Mullin have each been flagged for high transaction activity and strong reported returns in individual years. The New York Times investigation published in September 2022 identified 97 current members or their immediate family who had traded stocks in industries their committees regulated during 2019 to 2021, which established a baseline for the kind of overlap that characterizes active congressional trading.

Two caveats are essential before accepting any specific annual return figure. First, every industry return calculation uses disclosure midpoints and approximated execution prices, so each "annual return" is an estimate with wide uncertainty bounds. Second, the popular framing that compares a top member's estimated return to the S&P 500 or to a hedge fund benchmark is selecting on the extreme end of a distribution: in any given year, with 535 members producing thousands of trades, statistical outliers will exist. The more meaningful question is whether the aggregate, or the median active trader, beats the market, which is exactly what Eggers and Hainmueller examined and found the evidence for to be weaker than headlines suggest.

The cleanest real-world test of the "Congress beats the market" thesis is not a research paper. It is a pair of exchange-traded funds.

NANC and KRUZ: the test the market itself ran

The Subversive Capital and Unusual Whales partnership launched two ETFs on February 7, 2023, each designed to copy one party's disclosed congressional trades. The resulting multi-year performance record is the cleanest test of whether the outperformance effect survives when you try to capture it at scale.

NANC

Subversive Unusual Whales Democratic Trading ETF

Launched February 7, 2023. Holds positions in stocks purchased by Democratic members and their families, weighted by approximate disclosure size. Since inception, NANC has delivered returns in the general vicinity of the S&P 500, not the 60 to 70 percent annual headline figures attributed to individual top Democratic traders like the Pelosi household. The roughly 0.75 percent expense ratio applies annually. The fund exists, it trades, and it shows what happens when you try to systematically capture the Democratic side of congressional disclosures rather than cherry-picking the top performer.

KRUZ

Subversive Unusual Whales Republican Trading ETF

Launched the same day as NANC, using the same methodology applied to Republican disclosures. KRUZ has underperformed both NANC and the S&P 500 in most reporting periods since inception. Neither ETF has replicated the headline outperformance attributed to individual top traders in either party. Whatever edge exists in congressional trading is either concentrated in a tail of members who cannot be replicated at fund scale, or depends on execution speed that a 45-day-lagged ETF cannot access, or both.

Five structural reasons explain why the ETFs have failed to replicate the headline figures, and each of them applies to any attempt to systematically follow congressional trading at scale. First, diversification: the ETFs hold trades from roughly 150 members on each side. Top performers get washed out by average performers. Second, the 45-day disclosure lag: by the time a trade is disclosed, as much as a month and a half has passed. If the edge depends on timing relative to committee activity, the lag destroys most of it. Third, fee drag: 0.75 percent annually compounds against the strategy. Fourth, position sizing: if Paul Pelosi puts 20 percent of his portfolio into Alphabet call options, the ETF cannot match that concentration. Fifth, and most important, selection: the individual-return headlines describe the distribution's tail, not its center. Our analysis of NANC and the economics of copy-trading ETFs walks through these tradeoffs in full.

The ETF evidence does not say congressional trading has no edge. It says that the edge, to the extent it exists, lives in specific members, specific sectors, and specific trades, not in a broad pool that can be captured passively.

Six reasons the headline return figures are estimates, not measurements

Every widely cited "annual return" for a member of Congress is an approximation built on structural data gaps. These are the six biggest ones, and understanding them is the difference between citing a number accurately and reprinting a misleading one.

1

Amount brackets, not exact values

Disclosures use brackets: $1,001 to $15,000, $15,001 to $50,000, $50,001 to $100,000, $100,001 to $250,000, $250,001 to $500,000, $500,001 to $1 million, and upward. Analysts use midpoints. A disclosure of "$1M to $5M" could represent $1 million or $5 million, a five-fold range. Every return estimate inherits that uncertainty.

2

Approximated execution prices

Disclosures report the date of a transaction but not the actual execution price. Analysts use the closing price on the disclosed date as a proxy. Real executions can be materially different, especially for thinly traded stocks, options, or trades placed during volatile intraday windows.

3

The 45-day disclosure lag

Trades are disclosed up to 45 days after execution. Chronically late filings push the lag longer. Any return calculation that depends on comparing trade timing to contemporaneous market moves is operating on data that was up to a month and a half stale when it became public.

4

Options asymmetry

Options appear in disclosures as notional exposure, but their payoffs are nonlinear. A single correctly timed call option can generate returns of many hundred percent while expiring worthless options are common. Members who trade options heavily, such as the Pelosi household, have particularly noisy return estimates.

5

Member versus spouse versus trust

"Nancy Pelosi's return" is actually Paul Pelosi's return. "Ro Khanna's return" is his family's trust manager's return. A large share of the top-ranked "congressional returns" are really the returns of spouses, trusts, and professional managers whose activity is reportable because a member happens to be in Congress.

6

Selection and survivorship

Members who perform badly may reduce trading volume, leave Congress, or shift into blind trusts. Cross-sectional rankings capture who is trading actively, which is not a random sample of the chamber. Extreme performers on both tails are overrepresented in visible disclosure data relative to their statistical weight.

The honest answer, in three parts

First, "does Congress beat the market" is the wrong question. The median member of Congress does not actively trade stocks. They hold index funds, target-date retirement funds, and mutual funds that track the broad market by definition. Asking whether the median member beats the market is roughly equivalent to asking whether the market beats itself.

Second, for the active-trader subset, the aggregate evidence is mixed. Ziobrowski 2004 and 2011 found meaningful outperformance in pre-STOCK Act data. Eggers and Hainmueller 2013 found mediocre to poor performance in a later sample using more conservative methods. Neither paper's verdict is definitively correct. The fairest reading is that the effect exists but is smaller and less consistent than the popular narrative claims, and that it depends heavily on which members, which years, and which benchmark.

Third, the narrower claim that is best supported by the evidence is the Karadaş result: members tend to do better on trades that align with their committee assignments than on trades outside that alignment. This is the claim that makes sector-by-sector tracking worthwhile. It is also the claim that the Pelosi household's Alphabet and Amazon options during active antitrust enforcement, defense contractor trades by members of the Armed Services Committees, and pharmaceutical trades by members of Health committees are all specific instances of. The information advantage does not show up uniformly across every trade every member makes. It shows up where the member sits close enough to the relevant decisions to know something the public does not yet know.

Kapitol.ai's editorial premise is built on exactly that observation. Most congressional trades are noise. A small minority are signal. The difference is not member-level performance over some arbitrary period. It is committee alignment, legislative timing, and position specificity on a trade-by-trade basis.

Frequently asked questions

The most defensible answer is: some of them, on some trades, in some periods. The aggregate peer-reviewed evidence is contested, with Ziobrowski 2004/2011 finding meaningful outperformance and Eggers and Hainmueller 2013 finding the opposite on a different sample. The cleanest research design, Karadaş 2019, finds that members outperform specifically on trades aligned with their committee assignments. The NANC and KRUZ ETFs, which launched in February 2023 to copy congressional trades at scale, have not replicated the headline returns attributed to individual top traders. The honest answer is narrower than "yes" and narrower than "no."

Annual rankings from Unusual Whales and Quiver Quantitative consistently place the Pelosi household (Nancy and Paul Pelosi) near the top of the Democratic side, with Josh Gottheimer and the Khanna family trusts frequently in the upper quartile. On the Republican side, Mark Green, Kevin Hern, Tommy Tuberville, and Markwayne Mullin have each been flagged as top performers in individual years. The important caveat is that these rankings are built on disclosure-midpoint estimates and approximated execution prices, so the exact percentages reported in any given year are approximations with wide uncertainty bounds. Our most active traders index shows current transaction counts by member.

The evidence is mixed. If outperformance came primarily from informed trading on nonpublic information, the STOCK Act should have reduced it. Some post-2012 analyses do show declining outperformance. Others do not. The complicating factor is that the STOCK Act is disclosure legislation, not deterrence legislation. Fines for late disclosure are typically $200, and the SEC has not brought a successful insider trading case against a sitting member of Congress. So "post-STOCK Act" data does not represent "post-deterrent" behavior. It represents post-transparency behavior, which is a weaker constraint. For the full list of gaps, see the nine specific loopholes the STOCK Act leaves open.

Five structural reasons. Diversification across approximately 150 members washes out top performers. The 45-day disclosure lag means the ETF trades on information that is already a month and a half stale. The roughly 0.75 percent expense ratio compounds against the strategy annually. The ETF cannot match the concentration of individual member positions, so a 20 percent Alphabet allocation by one household gets diluted into a small fraction of the fund's weight. Finally, the headline individual returns come from the extreme tail of the distribution, not the median, and a broad ETF captures the median. Full analysis is in our NANC ETF review.

Ziobrowski 2004 is the most cited, because it was first and because its headline finding (85 basis points of monthly outperformance in the Senate) is the number the popular narrative built on. Eggers and Hainmueller 2013 is the most important counterweight, because it used more careful methodology on a later sample and reached the opposite conclusion. Karadaş 2019 is the most intellectually honest, because its committee-alignment framing is what the evidence actually supports. A rigorous citation of this literature should reference all three, acknowledge the Eggers and Hainmueller critique, and treat the Karadaş committee-alignment finding as the cleanest current answer rather than the broad "Congress beats the market" framing that headlines prefer.

The average trade is noise. The informative minority is what we curate.

Every trade we publish carries committee context, legislative timing, and a significance score. Not a data dump. Curated intelligence.

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