VOL. XCIV, NO. 247

★ A CURATED DIRECTORY OF FINANCIAL TOOLS ★

PRICE: 5 CENTS

Saturday, December 13, 2025

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Tool Comparison

Letters and Reviews vs Portfolio123 comparison

Compare pricing, supported platforms, categories, and standout capabilities to decide which tool fits your workflow.

Quick takeaways

Letters and Reviews adds 13F coverage that Portfolio123 skips.

Portfolio123 includes Screeners, Data Visualizations, Quant, Portfolio, Watchlist, Backtesting, Correlation, Financials, GDP, Interest Rates, Unemployment Rates, Consumer Sentiment, Housing & Construction, Data APIs, APIs & SDKs, Broker Connectors, Education, and Videos categories that Letters and Reviews omits.

In depth comparison

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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Portfolio123

portfolio123.com

Editor’s pick Hands-on review

Rules‑based quant research and portfolio‑management platform. Free Manage module covers multi‑account tracking, watchlists, and broker connectivity, while paid Research/DataMiner/API tiers unlock multifactor ranking, screening, long history backtests, AI Factor, and programmatic access. API & DataMiner use an API‑credit system with monthly caps that depend on your membership; the 21‑day paid Research trial excludes API/DataMiner and runs on a limited history slice.

Platforms

WebAPIDesktop

Pricing

FreeSubscription

Quick highlights

Web‑based quant research terminal for building multifactor ranking systems, stock/ETF screens, and complete rules‑based strategies with no programming, powered by point‑in‑time FactSet data and marketed as free of survivorship and look‑ahead bias.
Supports realistic simulations and backtests over roughly 20 years of history for US, Canadian, and European equities, with custom universes, separate buy/sell rules, position sizing, hedging, and “Book of Strategies” to combine and analyze correlated systems.
Stock & ETF coverage uses fundamentals, estimates, corporate actions, plus industry/sector classification, with “over 15,000 current US, Canadian, and European stocks” and many more historical issues.
AI Factor lets users train machine‑learning factors and plug them into ranking systems and strategies alongside traditional factors, with supporting API endpoints.
Manage module (free) provides portfolio/account tracking with real‑time quotes, multi‑account strategy tracking, stock timelines, integrated research views, and re‑imagined watchlists that chart watchlist performance vs benchmarks.

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Where they differ

Letters and Reviews

Distinct strengths include:

13F

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.

Portfolio123

Distinct strengths include:

Screeners Data Visualizations Quant Portfolio Watchlist Backtesting Correlation Financials

Web‑based quant research terminal for building multifactor ranking systems, stock/ETF screens, and complete rules‑based strategies with no programming, powered by point‑in‑time FactSet data and marketed as free of survivorship and look‑ahead bias.
Supports realistic simulations and backtests over roughly 20 years of history for US, Canadian, and European equities, with custom universes, separate buy/sell rules, position sizing, hedging, and “Book of Strategies” to combine and analyze correlated systems.
Stock & ETF coverage uses fundamentals, estimates, corporate actions, plus industry/sector classification, with “over 15,000 current US, Canadian, and European stocks” and many more historical issues.
AI Factor lets users train machine‑learning factors and plug them into ranking systems and strategies alongside traditional factors, with supporting API endpoints.

Feature-by-feature breakdown

Attribute	Letters and Reviews	Portfolio123
Categories Which research workflows each platform targets	Shared: Stock Ideas, Blogs Unique: 13F	Shared: Stock Ideas, Blogs Unique: Screeners, Data Visualizations, Quant, Portfolio, Watchlist, Backtesting, Correlation, Financials, GDP, Interest Rates, Unemployment Rates, Consumer Sentiment, Housing & Construction, Data APIs, APIs & SDKs, Broker Connectors, Education, Videos
Asset types Supported asset classes and universes	Stocks, ETFs	Stocks, ETFs, Closed-End Funds
Experience levels Who each product is built for	Beginner, Intermediate, Advanced	Beginner, Intermediate, Advanced
Platforms Where you can access the product	Web	Web, API, Desktop
Pricing High-level pricing models	Free	Free, Subscription
Key features Core capabilities called out by each vendor	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.	Unique Web‑based quant research terminal for building multifactor ranking systems, stock/ETF screens, and complete rules‑based strategies with no programming, powered by point‑in‑time FactSet data and marketed as free of survivorship and look‑ahead bias. Supports realistic simulations and backtests over roughly 20 years of history for US, Canadian, and European equities, with custom universes, separate buy/sell rules, position sizing, hedging, and “Book of Strategies” to combine and analyze correlated systems. Stock & ETF coverage uses fundamentals, estimates, corporate actions, plus industry/sector classification, with “over 15,000 current US, Canadian, and European stocks” and many more historical issues. AI Factor lets users train machine‑learning factors and plug them into ranking systems and strategies alongside traditional factors, with supporting API endpoints. Manage module (free) provides portfolio/account tracking with real‑time quotes, multi‑account strategy tracking, stock timelines, integrated research views, and re‑imagined watchlists that chart watchlist performance vs benchmarks. Broker connectivity enables sending orders from Portfolio123 to linked brokerage accounts (e.g., Interactive Brokers, Tradier), syncing holdings and fills automatically while keeping assets at your existing broker.
Tested Verified by hands-on testing inside Find My Moat	Not yet	Yes
Editor pick Featured inside curated shortlists	Standard listing	Highlighted

Frequently Asked Questions

Which workflows do Letters and Reviews and Portfolio123 both support?

Both platforms cover Stock Ideas, and Blogs workflows, so you can research those use cases in either tool before digging into the feature differences below.

Do Letters and Reviews and Portfolio123 require subscriptions?

Both Letters and Reviews and Portfolio123 keep freemium access with optional paid upgrades, so you can trial each platform before committing.

How can you access Letters and Reviews and Portfolio123?

Both Letters and Reviews and Portfolio123 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?

Letters and Reviews differentiates itself with 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., whereas Portfolio123 stands out for Web‑based quant research terminal for building multifactor ranking systems, stock/ETF screens, and complete rules‑based strategies with no programming, powered by point‑in‑time FactSet data and marketed as free of survivorship and look‑ahead bias., Supports realistic simulations and backtests over roughly 20 years of history for US, Canadian, and European equities, with custom universes, separate buy/sell rules, position sizing, hedging, and “Book of Strategies” to combine and analyze correlated systems., and Stock & ETF coverage uses fundamentals, estimates, corporate actions, plus industry/sector classification, with “over 15,000 current US, Canadian, and European stocks” and many more historical issues..

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