InsideArbitrage adds News, Alerts, Calendar, Acquisitions, Spin-offs, Buybacks & Authorizations, Dividends, Splits, Insider Data, Institutional Data, 13D/13G, Regulatory Filings Monitoring, Screeners, Data Visualizations, Portfolio, Watchlist, Newsletters, Videos, Playbooks & Case Studies, and PDF Annotation coverage that Letters and Reviews skips.
VOL. XCIV, NO. 247
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Friday, October 31, 2025
Tool Comparison
InsideArbitrage vs Letters and Reviews comparison
Compare pricing, supported platforms, categories, and standout capabilities to decide which tool fits your workflow.
Quick takeaways
Letters and Reviews includes Stock Ideas categories that InsideArbitrage omits.
In depth comparison
InsideArbitrage
insidearbitrage.com
Event‑driven research platform by Asif Suria focused on merger arbitrage, insider transactions, spinoffs, buybacks, activists, and related special situations. Premium includes tools like the Merger Arbitrage Tool, CVR database, buyback & spinoff trackers, premium screens (IA Score, cluster buys, ‘double dipper’), ‘Deals‑in‑the‑Works’ and deal calendars. IA Professional adds pro‑only features (e.g., CVR outcomes, activist tracker, reverse‑splits tracker, Insider Performance Score) and multi‑seat licensing.
Categories
Platforms
Pricing
Quick highlights
- Merger Arbitrage Tool with announced‑deal lists, spread tracking, calendars and deal updates; ‘Deals in the Works’ and deal post‑mortems.
- Insider data hub with ‘Insider Weekends’, cluster buys, buys near highs, flip‑floppers, top‑performing insiders and sector heat‑map.
- Buyback suite: daily buyback announcements, searchable buyback history, ‘Buyback Wednesdays’, and ‘Double Dipper’ (insiders + buybacks).
- Spinoff suite: upcoming/completed spinoffs and ‘Spinsider’ screen; CVR deals database with outcomes.
- Gurus/Institutional holdings pages aggregating 13F/13D/13G and Form 4 into manager dashboards.
Community votes (overall)
Letters and Reviews
lettersandreviews.blogspot.com
Free, personal curation site that aggregates **fund manager letters**, tickers mentioned in those letters, and **quarterly 13F** filer lists the author follows. Each quarter page links to original letters and maps tickers to quick‑reference pages; some 13F pages embed holdings tables and activity (new/increased/decreased/sold) for many managers. Also includes a small **Podcasts** list. No accounts, alerts, exports, or API—think link‑hub for primary sources rather than a data platform.
Categories
Platforms
Pricing
Quick highlights
- Quarterly **Fund Manager Letters** pages with the fund name, date, and a ‘Stocks Mentioned’ column (tickers link out for quick lookup).
- Quarterly **13‑F pages** the author reads, with many entries including holdings tables and position‑change flags (e.g., NEW / Sold Out / % of portfolio).
- Lightweight **About** page clarifies the goal: stock‑idea discovery from letters; author shares links and invites tips via @_iinvested.
- A small **Podcasts** page curating investing/finance episodes the author plans to re‑listen to.
Community votes (overall)
Where they differ
InsideArbitrage
Distinct strengths include:
- Merger Arbitrage Tool with announced‑deal lists, spread tracking, calendars and deal updates; ‘Deals in the Works’ and deal post‑mortems.
- Insider data hub with ‘Insider Weekends’, cluster buys, buys near highs, flip‑floppers, top‑performing insiders and sector heat‑map.
- Buyback suite: daily buyback announcements, searchable buyback history, ‘Buyback Wednesdays’, and ‘Double Dipper’ (insiders + buybacks).
- Spinoff suite: upcoming/completed spinoffs and ‘Spinsider’ screen; CVR deals database with outcomes.
Letters and Reviews
Distinct strengths include:
- Quarterly **Fund Manager Letters** pages with the fund name, date, and a ‘Stocks Mentioned’ column (tickers link out for quick lookup).
- Quarterly **13‑F pages** the author reads, with many entries including holdings tables and position‑change flags (e.g., NEW / Sold Out / % of portfolio).
- Lightweight **About** page clarifies the goal: stock‑idea discovery from letters; author shares links and invites tips via @_iinvested.
- A small **Podcasts** page curating investing/finance episodes the author plans to re‑listen to.
Feature-by-feature breakdown
| Attribute | InsideArbitrage | Letters and Reviews |
|---|---|---|
Categories Which research workflows each platform targets | Shared: 13F, Blogs Unique: News, Alerts, Calendar, Acquisitions, Spin-offs, Buybacks & Authorizations, Dividends, Splits, Insider Data, Institutional Data, 13D/13G, Regulatory Filings Monitoring, Screeners, Data Visualizations, Portfolio, Watchlist, Newsletters, Videos, Playbooks & Case Studies, PDF Annotation | Shared: 13F, Blogs Unique: Stock Ideas |
Asset types Supported asset classes and universes | Stocks, ETFs | Stocks, ETFs |
Experience levels Who each product is built for | Beginner, Intermediate, Advanced | Beginner, Intermediate, Advanced |
Platforms Where you can access the product | Web | Web |
Pricing High-level pricing models | Free, Subscription | Free |
Key features Core capabilities called out by each vendor | Unique
| Unique
|
Tested Verified by hands-on testing inside Find My Moat | Not yet | Not yet |
Editor pick Featured inside curated shortlists | Standard listing | Standard listing |
Frequently Asked Questions
Which workflows do InsideArbitrage and Letters and Reviews both support?
Both platforms cover 13F, and Blogs workflows, so you can research those use cases in either tool before digging into the feature differences below.
Do InsideArbitrage and Letters and Reviews require subscriptions?
Both InsideArbitrage and Letters and Reviews keep freemium access with optional paid upgrades, so you can trial each platform before committing.
How can you access InsideArbitrage and Letters and Reviews?
Both InsideArbitrage and Letters and Reviews prioritize web or desktop access. Investors wanting a mobile-first workflow may need to rely on responsive web views.
What unique strengths set the two platforms apart?
InsideArbitrage differentiates itself with Merger Arbitrage Tool with announced‑deal lists, spread tracking, calendars and deal updates; ‘Deals in the Works’ and deal post‑mortems., Insider data hub with ‘Insider Weekends’, cluster buys, buys near highs, flip‑floppers, top‑performing insiders and sector heat‑map., and Buyback suite: daily buyback announcements, searchable buyback history, ‘Buyback Wednesdays’, and ‘Double Dipper’ (insiders + buybacks)., whereas Letters and Reviews stands out for Quarterly **Fund Manager Letters** pages with the fund name, date, and a ‘Stocks Mentioned’ column (tickers link out for quick lookup)., Quarterly **13‑F pages** the author reads, with many entries including holdings tables and position‑change flags (e.g., NEW / Sold Out / % of portfolio)., and Lightweight **About** page clarifies the goal: stock‑idea discovery from letters; author shares links and invites tips via @_iinvested..
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Curation & Accuracy
This directory blends AI‑assisted discovery with human curation. Entries are reviewed, edited, and organized with the goal of expanding coverage and sharpening quality over time. Your feedback helps steer improvements (because no single human can capture everything all at once).
Details change. Pricing, features, and availability may be incomplete or out of date. Treat listings as a starting point and verify on the provider’s site before making decisions. If you spot an error or a gap, send a quick note and I’ll adjust.