May 17, 9:33 am
Corporate insiders file thousands of Form 4s every year. Most of them are noise. Executives sell to cover taxes, directors cash out vested options, and institutional holders trim on schedule. The signal gets buried under the paperwork.
But every once in a while, the paperwork tells a story. A Co-CEO spending $4.4 million on his own company's stock during a 25% drawdown. A shipping CEO buying shares every single trading day for two months straight. A billionaire amassing $1.4 billion in synthetic exposure to a stock that's down 55% from its highs. These aren't scheduled dispositions. These are conviction trades.
We pulled every insider transaction filed in 2026 across the U.S. market and ranked stocks by the strongest insider buying signals, not just by dollar volume (which can be skewed by a single institutional block trade), but by a combination of factors: the number of unique buyers, the frequency of purchases, the ratio of buys to sells, and the seniority of the insiders involved.
Six stocks stood out from the rest.
Before diving into the names, it's worth understanding why we focus exclusively on buying. Insider selling is common, routine, and usually meaningless. Executives sell stock for mortgages, for diversification, for taxes, for divorce settlements. There are a hundred reasons to sell that have nothing to do with a company's prospects.
Academic research has consistently shown that insider purchases outperform the broader market. A landmark study by Lakonishok and Lee found that stocks with heavy insider buying outperformed by an average of 4.8% annually over the following twelve months. The signal is strongest when multiple insiders buy in a short window, when the purchases are large relative to the insider's existing holdings, and when they come during periods of stock price weakness.
All six stocks on this list check at least two of those boxes. Several check all three.
| Stock | Signal Type | Key Buyer(s) | Mkt Cap | Buy Txns | Net Buy Value | AI Score |
|---|---|---|---|---|---|---|
| KKR KKR & Co | C-Suite Cluster | Both Co-CEOs + 3 Directors | $91.5B | 13 | $50.9M | |
| FLUT Flutter Ent. | Whale Accumulation | Kenneth Dart (billionaire) + 7 others | $16.0B | 44 | $1.4B+ | |
| RSG Republic Svcs | Whale Accumulation | Bill Gates / Cascade Investment | $64.2B | 7 | $100.5M | |
| NMM Navios Maritime | Daily CEO Buying | CEO Angeliki Frangou | $2.0B | 40 | $3.3M | |
| AMR Alpha Met. | Contrarian Buy | Director Kenneth Courtis | $2.3B | 32 | $13.4M | |
| WRB W.R. Berkley | Strategic Stake | Mitsui Sumitomo Insurance (Japan) | $24.7B | 85 | $601M |
AltIndex Insider Transaction Data · SEC Form 4 Filings
Price
$96.97
P/E
33.4x
YTD
-7.7%
All-Time High
$170.40
Unique Buyers
5
This is the cleanest insider buying signal on the list. In late February and early March 2026, five separate KKR insiders bought stock on the open market, and none of them sold a single share. The buyers include Co-CEO Joseph Bae ($17.2M across 5 purchases starting at $88.56/share), Co-CEO Scott Nuttall ($17.2M across 4 purchases starting at $87.81), director Timothy Barakett ($10.0M across 2 purchases), director Matt Cohler ($4.5M at $102.90), and director Mary Dillon ($2.0M at $90.96), combining for over $50.9 million in open-market purchases.
The timing is what makes this signal so compelling. KKR's stock had dropped 25% from its January 2025 all-time high of $170.40, pressured by a Q4 2025 earnings miss, a $350 million clawback charge on its Asia II fund, and multiple analyst downgrades including UBS slashing its price target from $168 to $125. The narrative was turning bearish, but the people who run the firm didn't agree with it.
| Insider | Role | Shares | Avg Price | Value |
|---|---|---|---|---|
| Joseph Y. Bae | Co-CEO | 175,000 | $98.30 | $17.20M |
| Scott C. Nuttall | Co-CEO | 175,000 | $98.42 | $17.22M |
| Timothy R. Barakett | Director | 100,000 | $99.70 | $9.97M |
| Matt Cohler | Director | 43,872 | $102.90 | $4.51M |
| Mary N. Dillon | Director | 22,225 | $90.96 | $2.02M |
The financials back up the conviction handsomely. KKR's Q1 2026 total revenue came in at $4.3 billion with adjusted EPS of $1.39, beating the consensus estimate of $1.28, while AUM hit $758 billion (up 14% year over year) and fee-related earnings grew 23%. The analyst consensus remains a Buy with an average price target of $130, roughly 34% above the current price, and our AI Score for KKR sits at 70, which puts it in buy territory and makes it the highest-scoring stock on this list. When both Co-CEOs buy at the same price where analysts see 34% upside, the alignment between insider knowledge and outside analysis is hard to ignore.
Price
$92.38
52W High
$313.69
Drawdown
-55%
Analyst Target
$196
Unique Buyers
8
Kenneth Bryan Dart is not a household name, but the 70-year-old heir to the Dart Container fortune has built a reputation as one of the most aggressive investors in global markets. Since September 2025, Dart has filed over 40 Form 4s with the SEC disclosing total return swaps on Flutter Entertainment stock, cash-settled derivatives that give him full economic exposure to Flutter's price movements without voting rights. Through entities named Lake Michigan Limited and LBS Limited, Dart has amassed synthetic exposure to over 15.2 million Flutter shares, worth approximately $1.4 billion at current prices.
The stock has been hammered by prediction market competition, state tax increases on sports betting, and the departure of FanDuel CEO Amy Howe in May 2026. But what makes this particularly notable is the breadth of insider buying alongside Dart's massive position: eight unique insiders have purchased FLUT stock in 2026, including Flutter CEO Jeremy Jackson, Flutter International CEO Daniel Taylor, and board member Carolan Lennon, all of whom made direct open-market purchases alongside the billionaire's derivative accumulation.
The fundamentals are strained but not broken, with Q1 2026 revenue of $4.3 billion (up 17% year over year) and EBITDA of $817 million from the world's largest online sports betting and iGaming operator. With 22 analysts maintaining a Buy consensus and a median price target of $196 (representing over 100% upside), the gap between the current price and Wall Street's target is enormous. Our AI Score for FLUT is 47, in hold territory, and the disconnect between a low overall score and aggressive insider buying is itself a signal worth watching: insiders may be seeing something the aggregated data hasn't caught up to yet.
AltIndex Insider Transaction Data
Price
$208.32
P/E
29.9x
Dividend
1.21%
Gates Ownership
35.6%
May Purchases
$100.5M
Through his investment vehicle Cascade Investment LLC, Bill Gates already owned 35.6% of Republic Services as of February 2026, making him the company's largest shareholder by a wide margin. So when Cascade filed a Form 4 in May showing $100.5 million in fresh open-market purchases (499,150 shares at weighted-average prices between $197.18 and $203.67), it raised a clear question: why would someone who already owns more than a third of a $64 billion waste management company keep buying near the 52-week low?
The answer likely lies in Gates's decade-long accumulation pattern. Cascade started buying Republic Services in the early 2010s and has added shares in virtually every pullback since, treating the company as a generational compounder in an industry with high barriers to entry, long-term municipal contracts, and near-guaranteed demand. Republic Services has beaten EPS estimates in four of the last five quarters, and revenue has grown every single quarter for the past two years.
Cascade Investment (Bill Gates) Ownership of Republic Services Over Time
Our AI Score for RSG sits at 53, in hold territory, with EBITDA margins remaining above 30% and consistent revenue growth underpinning the score. For an investor like Gates, who famously thinks in decades rather than quarters, the $100 million addition at a near-low price point looks like a classic Cascade play: boring business, boring stock, and reliably boring money.
Price
$71.65
P/E
7.4x
1Y Low
$36.62
Fleet Size
170 vessels
Daily Buys
40
The CEO, Chairman, and 17.7% owner of Navios Maritime Partners has filed 40 insider buy transactions in 2026, purchasing approximately 1,100-1,200 common units daily through a Rule 10b5-1 trading plan with UBS Financial Services. The purchases are small individually (roughly $82,000-$87,000 per day), but the pattern is relentless: from early March through mid-May, Angeliki Frangou has added units on virtually every single trading session, a level of systematic conviction that stands apart from the large block buys at KKR or Flutter.
The stock deserves the attention that Frangou's buying pattern demands. Navios operates 170 vessels across dry bulk, containership, and tanker segments, making it one of the most diversified shipping fleets in the world. The company trades at a P/E of just 7.4x (a fraction of the broader market), with revenue growing from $304 million to $366 million per quarter over the last year and Q4 2025 EPS of $3.40 comfortably beating analyst estimates.
Navios Maritime Partners (NMM) Fleet Growth
Our AI Score for NMM is 55, supported by strong fundamentals including the combination of robust earnings, low valuation multiples, and improving revenue trajectory. The shipping sector often trades at a persistent discount to fundamentals due to its cyclical reputation, but Frangou appears to be betting that the current valuation gap has grown too wide to ignore.
Price
$179.69
Q1 EPS
-$0.86
Loss Quarters
4 straight
Insider Buys
32
Insider Sells
2 (minor)
This is the most contrarian insider trade on the list. Alpha Metallurgical Resources, one of the largest metallurgical coal producers in the U.S., has posted net losses for four consecutive quarters with Q1 2026 EPS of -$0.86 and revenue declining from $804 million in Q2 2024 to $525 million in Q1 2026. None of that has slowed director Kenneth S. Courtis, a former Goldman Sachs Asia strategist with deep expertise in commodity cycles, who has filed 32 separate buy transactions in 2026 totaling approximately $13.4 million.
Courtis bought 25,000 shares in a single day on March 9, then 15,000 more the next day, then 10,000 the day after that. He bought again in May at $182-$192 per share, bringing his direct holdings to 975,394 shares, and over the past year has purchased 230,000 shares without selling a single one. His thesis appears to be a bet on the metallurgical coal cycle turning: steel production requires met coal, and while thermal coal faces long-term decline, met coal remains critical to steelmaking until green steel technology reaches commercial scale.
Alpha Metallurgical Resources (AMR) Quarterly EPS
Our AI Score for AMR is 52, reflecting the fundamental weakness in the current cycle. But the stock has already risen 66% from its early-2026 lows, suggesting the market may be starting to agree with Courtis's reading of the commodity cycle. A director buying $13 million of a money-losing company with his own capital is either deeply informed about the cycle's trajectory or deeply misguided, and given Courtis's track record in Asian industrial commodities, the evidence leans toward the former.
Price
$66.45
P/E
14.1x
Stake Size
15.7%
Deal Value
$3.8B
Buy Txns
85
This is a different category of insider buying altogether. Mitsui Sumitomo Insurance, a subsidiary of Japan's MS&AD Insurance Group (one of the world's largest P&C insurers), has filed 85 buy transactions on WRB since late December 2025, completing a $3.8 billion strategic stake acquisition that brings its ownership to 15.7% of the company. The deal was announced in late 2025 as a structured partnership with the Berkley family, with Mitsui Sumitomo acquiring 8.7 million shares at prices between $66 and $73 entirely on the open market through a Rule 10b5-1 plan with Jefferies, and designating executive Andrew Carrier to the W.R. Berkley board as part of the governance arrangement.
For investors tracking insider trading signals, the message here is strategic validation from a sophisticated institutional buyer rather than a traditional C-suite purchase. Mitsui Sumitomo didn't commit $3.8 billion to a 15.7% stake in a U.S. insurer on a whim: it sees W.R. Berkley as a long-term partner in the global P&C insurance market, which is experiencing hard pricing conditions and growing demand. The Japanese conglomerate also recently acquired an 18% stake in MassMutual's Barings, signaling a broader and deliberate push into U.S. financial services.
W.R. Berkley (WRB) Quarterly Revenue
The financials support the strategic thesis, with W.R. Berkley beating EPS estimates in four of the last five quarters (Q1 2026 EPS of $1.30 came in well above the $1.14 consensus), total revenue growing from $3.3B to $3.7B per quarter over the last two years, and the stock trading at just 14.1x earnings. Our AI Score for WRB is 47, in hold territory, but when a $200 billion Japanese conglomerate commits $3.8 billion to a structured partnership with a U.S. insurer, the signal carries weight well beyond what any quantitative score can capture on its own.
Not all insider buying signals are created equal. A Co-CEO buying into a 25% drawdown with a high AI Score is a fundamentally different opportunity than a director buying shares of a stock that's already up 35% on the year. To help cut through the noise, we built a composite ranking that weighs three factors:
AltIndex Buying Opportunity Score
A few caveats worth noting. This ranking reflects the current snapshot and should be one input among many. FLUT scores highest largely because the 49% YTD decline creates an enormous entry window, but that decline happened for real reasons (prediction market competition, management turnover, regulatory risk). The AI Score of 47 is telling you the underlying data signals are mixed. Conversely, KKR ranks second but may be the better risk-adjusted opportunity: its AI Score of 70 means the alternative data and fundamentals are aligned with the insider buying, a rarer and more powerful combination.
These six stocks represent very different types of insider conviction: C-suite cluster buying (KKR), billionaire derivative accumulation (Flutter), patient whale-scale position building (Republic Services), methodical daily purchases (Navios), contrarian bets against the current earnings cycle (Alpha Metallurgical), and strategic cross-border partnerships (W.R. Berkley).
What they share is a willingness by informed insiders to put significant personal capital at risk, the strongest signal available in public market filings. Insider buying doesn't guarantee a stock will go up. But it narrows the odds. And when the buyers are Co-CEOs, billionaires, and sophisticated institutional partners making purchases measured in the hundreds of millions, it's worth paying attention.
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