InsiderAction.io vs OpenInsider: An Honest Comparison

Why Write This?

If you track insider trades, you have almost certainly used OpenInsider. It has been around for years, it's free, and for a lot of investors it is simply where Form 4 data lives. I've used it a lot myself, and it's part of the reason InsiderAction.io exists.

So it's a fair question: why would you use this site instead? This article is my attempt at an honest answer. That includes the things OpenInsider still does better. Obviously I'm biased, so check both and decide for yourself.

The Short Version

OpenInsider is a dense, fast, no-frills screener with a long menu of ready-made lists. If you like scanning big tables and want a preset view one click away, it is excellent.

InsiderAction.io now has a screener that covers almost everything OpenInsider's does, and adds context on top: whether the insider has a good track record, what the whole industry is doing, and what a filing adds up to rather than its individual lines.

Most serious users will probably end up using both.

Side by Side

Where OpenInsider Still Wins

Preset lists. The menu is full of ready-made views: latest cluster buys, penny stock buys, officer purchases over $25k, CEO/CFO sales over $100k, top insider purchases of the day, week and month. Bookmark the one you like and you're done. We have fewer of these. You can build most of them in our screener and bookmark the result, but that takes a minute the first time.

A few screening options we don't have. OpenInsider can group results by company or insider and filter on how many insiders or filings are involved, which is effectively a custom cluster screen. It also filters on liquidity and on SIC code ranges. We have a clusters page instead of the grouping option, and no liquidity filter.

Longer date ranges. OpenInsider lets you screen across all dates in one go. We let you pick any custom range back to 2015, but one screen can cover at most six months, unless you pick specific tickers, in which case any length works. To look at a whole year, run two half-year screens. The limit keeps the database fast for everyone.

Speed and density. It's plain HTML and loads instantly. You see a lot of rows on one screen. Some people love that, and I get it.

Where InsiderAction.io Is Different

A screener built on filings, not lines

A single Form 4 often contains many lines. An insider might sell in ten lots on the same day at slightly different prices. We add those lines up into one row per filing, so a $500k sale shows up as one $500k sale and not as ten $50k fragments. Every filter in our transaction database works on those filing totals: value, average price, ownership change and filing delay.

So a question like "CFO purchases over $100k in the last three months where ownership rose by at least 20%" is one screen, and it filters on what each CFO actually did in each filing. Open the Advanced panel for transaction codes, titles, tickers, ranges, filing dates and sorting. Every setting goes into the URL, so you can bookmark or share a screen.

Who is buying, not just what was bought

OpenInsider's screener has columns for the stock's move 1 day, 1 week, 1 month and 6 months after a trade, but when we checked in October 2026 they were empty on every row, including trades from early 2025. We measure what happened after each purchase and score the insider across all of their trades. The Insider Signal Score (ISS) combines an insider's win rate, average returns, conviction and track record length into one number, and you can screen on it. A buy from someone with a long record of well-timed purchases is worth more attention than a buy from someone whose purchases usually lose money. And the low scorers can be just as interesting, as a contrarian signal.

Industry-level signals

This is the main reason I built the site. OpenInsider groups companies by SIC code, an old government classification. We use GICS-style sectors and industries, the kind of grouping most investors and index providers work with, and we aggregate insider buying and selling across every company in each sector and industry.

That lets you answer questions a per-stock screener can't answer easily. Are insiders across regional banks buying right now? Has biotech had net insider buying for several months in a row? The sector pages show the aggregates, and the streaks page highlights industries where insider buying has kept going month after month. Read more in our industry buying streaks guide.

Watchlist alerts

Add tickers to your watchlist and you'll get an email when a new Form 4 is filed for one of them. If you already follow a list of stocks, you don't have to keep checking back.

Explanations next to the data

We also write guides like this one. If you're newer to insider data, start with how to read a Form 4 or our guide to Form 4 transaction codes. Our methodology page explains exactly how every number on the site is calculated.

Where We're Behind

To be fair, there are things we don't do (yet):

• Fewer one-click preset lists, and no penny stock buys view.
• No grouping with count thresholds, liquidity filter or SIC range filter in the screener.
• One screen covers at most six months (anywhere back to 2015), unless you choose specific tickers.

If one of these matters to you, tell us. The feature list is largely driven by what users ask for.

Which Should You Use?

• You want a ready-made list one click away: OpenInsider.
• You want a specific screen on filing totals, with filing dates and delays: either works. On InsiderAction.io, use the Advanced panel in the database.
• You want to know if the insider is any good at this: InsiderAction.io, via ISS.
• You want to see where insiders are buying across an industry or sector: InsiderAction.io, via sectors and streaks.
• You want an email when insiders trade your stocks: InsiderAction.io watchlist.
• You want both: Use both. They're free, and they read the same SEC filings.

Both sites get their data from the same place, the SEC's EDGAR system. The difference is in what each one does with it. Whatever you use, insider trades are a starting point for research, not a buy signal by themselves.

OpenInsider is an independent site not affiliated with InsiderAction.io. Feature comparison based on publicly visible features as of October 2026.