undamentalytics Newsletter

Brown Joseph W: insider trades

Chief executive, Director at 2 companies we cover. 16 open-market purchases and 2 sales not made under a pre-set plan, reported from November 18, 2010 to November 26, 2025.

Would copying Brown Joseph W’s purchases have beaten the S&P 500?

Too few purchases to judge. Only 15 purchases have 12 months of prices after the report; we judge insiders once they have 20. The figures below can swing a long way on a handful of trades. Buying each purchase the day after it was reported, an equal amount each, and holding it 12 months or until they reported a sale would have turned $10,000 on November 19, 2010 into $7,189 by November 2, 2026, −2.0% a year. The copy held shares only 55% of the time, so the fair comparison is the S&P 500 on those same days with Treasury bills otherwise: $19,588, +4.3% a year (the S&P 500 held throughout made $83,285, +14.3% a year). Beta against the index was 0.37. Twelve months after each report, the average purchase was −9.4% against the S&P 500 (median −11.8%), and 33% beat it. Measured from the trade date, the insider’s own timing, the average was −8.8%. After their sales, the shares moved +10.0% against the index over 12 months on average (a negative figure means selling was the right call); 50% trailed it.

With 296 insiders tested, some will look skilled or unskilled by chance alone: when we replaced each insider’s stocks with random companies bought on the same days, about 5.7 cleared the bar ahead and 23.3 behind. One record on its own proves little.

$0$25.0k$50.0k$75.0k 201020122014201620182020202220242026 $83.3k$19.6k$7.2k
Copying Brown Joseph WS&P 500, same days investedS&P 500, held throughout $10,000 copying Brown Joseph W’s open-market purchases from November 19, 2010, before costs and taxes, marked weekly. Each purchase gets the same starting stake, bought at the close of the first trading day after the report and sold 12 months later or the day after a reported sale of that stock; uninvested money earns the Treasury bill rate. “Same days invested” holds the S&P 500 only on the days the copy held shares, Treasury bills otherwise.
Return a year, copying
−2.0%
S&P 500, same days invested
+4.3% (held throughout +14.3%)
Time in shares
55%
Sharpe ratio (S&P 500)
0.03 (0.78)
Biggest drop (S&P 500)
−65% (−34%)
Market sensitivity (beta)
0.37
Purchases copied
16

Trade by trade

Brown Joseph W: trades against the S&P 500 afterwards
MeasuredTrades countedAverage vs S&P 500MedianWent the right wayYearst-statisticp-valueEvidence
Purchases, 3 months after the report 16 −2.4% −5.4% 25% 9 −0.24 0.82 No reliable evidence
Purchases, 6 months after the report 16 −6.6% −8.6% 38% 9 −1.04 0.33 No reliable evidence
Purchases, 12 months after the report 15 −9.4% −11.8% 33% 9 −1.18 0.27 No reliable evidence
Purchases, 12 months after the trade 15 −8.8% −16.9% 33% 9 −1.04 0.33 No reliable evidence
Sales, 3 months after the report 2 +4.7% +4.7% 50% 2 — — Not enough years
Sales, 12 months after the report 2 +10.0% +10.0% 50% 2 — — Not enough years
Sales, 12 months after the trade 2 +8.0% +8.0% 50% 2 — — Not enough years

“Average vs S&P 500” is the stock’s return including dividends minus the index’s over the same dates, from the close on the first trading day after the report, or from the close on the trade date. Only windows that have finished are counted. For sales, a negative figure means the stock lagged after it was sold, so selling was the right call (green). “Went the right way” is the share of purchases that beat the index, or of sales that trailed it. The t-statistic uses one average per year of reports, because one person’s trades bunch into the same stock and weeks, and needs trades in at least four different years; the p-value comes from the t distribution with that number of years (with four years, a t of 2 has p = 0.14). “Some evidence” means p under 5%, “strong evidence” p under 1% over at least six years.

Companies traded

CompanyTitle on the latest filingPurchasesSalesFirst reportLatest report
Global Indemnity Group, LLC GBLI Chief Executive Officer110May 12, 2017November 26, 2025
Mbia Inc MBI Chief Executive Officer52November 18, 2010December 20, 2017

Trades and what followed

Moves are against the S&P 500; green means the trade went the insider’s way.

ReportedTradedCompanyTradeValue3 months after report12 months after report12 months after trade
November 26, 2025November 25, 2025 GBLI Purchase $129,900 +3.2%not yetnot yet
August 22, 2025August 20, 2025 GBLI Purchase $60,000 −9.5%−16.3%−22.5%
August 13, 2025August 11, 2025 GBLI Purchase $161,500 −5.8%−21.9%−16.9%
May 15, 2025May 14, 2025 GBLI Purchase $150,000 −9.2%−28.8%−29.8%
May 14, 2025May 12, 2025 GBLI Purchase $142,250 −10.0%−29.1%−25.7%
May 17, 2024May 15, 2024 GBLI Purchase $64,000 −3.4%−6.7%−11.5%
May 15, 2024May 13, 2024 GBLI Purchase $259,760 −4.9%−11.4%−18.6%
August 22, 2022August 18, 2022 GBLI Purchase $258,500 0.0%+38.0%+37.5%
May 19, 2022May 17, 2022 GBLI Purchase $266,900 −9.4%+3.9%+0.1%
November 16, 2021November 12, 2021 GBLI Purchase $541,500 +7.9%+7.5%+12.4%
December 20, 2017December 19, 2017 MBI Purchase $362,500 +17.8%+10.4%+22.1%
May 12, 2017May 11, 2017 GBLI Purchase $77,000 −1.2%−11.8%−13.3%
December 31, 2015December 31, 2015 MBI Sale $194,700 +22.8%+53.2%+53.1%
June 22, 2015June 19, 2015 MBI Purchase $673,303 −20.7%−27.9%−26.2%
June 3, 2014June 3, 2014 MBI Purchase $728,109 −21.4%−37.3%−33.0%
May 24, 2013May 23, 2013 MBI Sale $10,860,500 −13.4%−33.3%−37.2%
September 2, 2011September 2, 2011 MBI Purchase $760,000 +34.7%+22.1%+22.0%
November 18, 2010November 18, 2010 MBI Purchase $1,000,000 −5.8%−32.2%−28.1%

Open-market purchases and sales of at least $10,000 in companies we cover, from SEC Form 4 filings; sales made under a pre-set Rule 10b5-1 plan are not shown. “Not yet” means the window has not finished or the share price was under $5 at entry. These are the shares’ moves after each trade: they say nothing about why Brown Joseph W traded and do not suggest the use of non-public information. How every insider compares · the insider trading backtest.