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Better Insider Signals, Smarter Peer Comparisons and a Weekly AI Portfolio Summary

  • September 30, 2026

Since the start of this year, we have been working hard to build new features and battling the AI bots at InsideArbitrage as discussed in our January 2026 update: Top Ranking CEOs, Redesigned Deal Metrics Page and a Whole Lot More.

One of these projects was very ambitious and one of our developers recently burned through 380 million tokens in a few weeks, depositing a small chunk of change into Anthropic’s coffers. While that project is yet to come to fruition, here are some quick notes from the latest InsideArbitrage release, which includes our redesigned Insider Buying page, the inclusion of modifiable peers in our quote pages and an enhanced My Portfolio feature that allows you to receive an AI summary about your portfolio by email every Saturday.

Insider Buying and Selling

Earlier this week I was excited to see an insider purchase come through at one of the world’s largest derivatives marketplaces, The CME Group (CME). An independent director buying stock on the open market is often a strong signal, especially if he has served on the board since 1997 and has been a member of the Chicago Mercantile Exchange for more than 45 years.

When I pulled up the Form 4 filing, my excitement plunged. The buy was not an open market purchase. It was instead a broker-administered dividend reinvestment and you can see this in footnote 2 of the filing.

CME Group Insider Purchase Dividend Reinvestment

This is exactly the kind of transaction that can look bullish in a raw insider feed but is not actually an opportunistic insider buy.

This is one of many reasons I have been closely reviewing the actual Form 4s filed with the SEC and their footnotes almost every weeknight for the last 16 years. Here are a few things we have noticed with insider purchases that make it difficult to distill the signal from the noise if you are looking at these transactions only at a surface level:

  • The insider purchasing shares is simply moving stock from one account to another for estate planning purposes (Globalstar)
  • The insider is selling one class of shares to buy a different class that either provides more voting power (First Citizens Bancshares) or a better dividend (Greif)
  • The insider purchase is not a real purchase but is a sale that was erroneously filed as a buy. I discussed a filing with the COO of a company at an investor conference and walked him through why I felt that his purchase was most likely a sale. He acknowledged the mistake and asked the company to file an amended Form 4 to fix the problem.
  • The purchase is not an opportunistic buy but part of an established 10b5-1 plan where the insider will buy consistently over a period of several weeks or months (Navios Maritime)
  • Instead of filing the purchase within two business days of the trade, the filing is weeks, months or in some cases, several years late
  • The company has set up programmatic purchases (Employee Stock Purchase Plans, Director Compensation Plans, etc.)
  • The purchases are of preferred shares instead of common stock, or, in some cases, both preferred and common share purchases are in the same filing (Liberty Latin America)

Our redesigned Insider Buying and Insider Selling pages on InsideArbitrage surface many of these nuances immediately, so you can spend less time opening Form 4s and more time focusing on the purchases that may actually matter.

Our new pages now include legends right below the company name that call out that the insider buying is part of a cluster of purchases by multiple insiders within a 30 day period, whether the filing has been amended, whether the purchase is part of a 10b5-1 plan, whether the purchase was filed late and more. You can see this in action below or check it out on our Insider Buying page.

Insider Buying September 28 2026

We also made it easier to search for specific companies or insiders as well as filter the list based on CEO purchases, CFO purchases, high value purchases (over $1 million) and a whole lot more.

Insider Buying Filters - InsideArbitrage

Peer Comparison ($)

When we are evaluating a new merger arbitrage idea, buyback candidate or special situation, one of the first things we want to know is how the company compares with the businesses investors are actually valuing alongside it. The new Peers tab on our quote pages lets paying subscribers build that comparison set themselves instead of being stuck with a generic peer group.

The updated peer list is “sticky” and does not revert back to the default for logged-in subscribers. Here is a small list of peers I created for the coffee chain Dutch Bros. (BROS).

Dutch Bros. Peers

AI Summary of My Portfolio ($)

The My Portfolio Plus feature, which we launched in August 2024 to allow you to create your own portfolios and receive alerts by email about SEC filings, valuation thresholds, etc. has been enhanced. Subscribers can now see news and a curated list of SEC filings (8-K, 10-K, 10-Q, 13D, etc.) related to their portfolios at the bottom of the portfolio.

If there are less than 20 stocks in the portfolio, you can also see an AI generated summary of the portfolio with a look back period of one week, two weeks or one month. For investors following dozens of positions, keeping up with every filing and company-specific development can become a job of its own. The new AI portfolio summary pulls together the most important developments across your holdings and can deliver them to your inbox every Saturday.

AI Portfolio Summary

While frontier AI models have improved a lot over the last two years, they still continue to hallucinate. During our multiple rounds of testing, we found in one instance that the AI fabricated an earnings report and in another instance falsely claimed that the Fed had recently cut interest rates. Through careful model selection, curated prompts and other techniques, we have reduced the number of hallucinations but as they teach new managers: “trust but verify”.

Despite these drawbacks, I personally found the AI summary very useful and we plan to continue iterating on this feature to improve the reliability of the AI summary.

If you are already using InsideArbitrage to track insider activity, special situations or your portfolio, these updates are designed to help you get to the important information faster and filter out more of the noise.

Free subscribers can try the new AI portfolio summary through the end of the year. Paying subscribers also get access to editable peer comparisons and the broader set of premium tools across the platform.

You can explore the new features today, and if they save you even a few hours of research each month, upgrading may quickly pay for itself. You can check out our subscription plans here.

We have some exciting new features and a completely new vertical currently in development that we plan to release in Q1 2027.

Disclaimer: I hold long positions in Globalstar and Liberty Latin America Series A preferreds. Please do your own due diligence before buying or selling any securities mentioned in this article. We do not warrant the completeness or accuracy of the content or data provided in this article.