VOL. XCIV, NO. 247

★ FINANCIAL TOOLS & SERVICES DIRECTORY ★

PRICE: 5 CENTS

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

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.

Letters and Reviews includes Stock Ideas categories that InsideArbitrage omits.

In depth comparison

InsideArbitrage logo

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.

Platforms

Web

Pricing

FreeSubscription

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.

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Letters and Reviews logo

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.

Platforms

Web

Pricing

Free

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.

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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

AttributeInsideArbitrageLetters 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

  • 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.
  • Event‑driven monitor & M&A news feed; earnings calendar; tender‑offers tracker; activist‑campaign tracker; C‑suite transitions tool.

Unique

  • 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.
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..

Keep exploring

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.