★ BEST INVESTING TOOLS COMPARISON ★

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Tool comparison edition

Tool Comparison

Portfolio123 vs Stock Spinoff Investing

Portfolio123 logo

Portfolio123

portfolio123.comPickTested

Best for screeners and data visualizations

Free • From $25/mo

versus
Stock Spinoff Investing logo

Stock Spinoff Investing

stockspinoffinvesting.com

Best for calendar and corporate actions & special situations

Free • From $58.08/mo

Portfolio123Stock Spinoff Investing
WebAPIDesktopPlatformsWeb
+2 (4)CommunityNo votes yet

Outbound links may include affiliate or sponsor codes.

The verdict

The bottom line

Portfolio123 and Stock Spinoff Investing cover a lot of the same ground (3 shared categories, stock ideas, blogs, and videos), so for the basics you won't go far wrong with either. Portfolio123 simply does more: 19 categories to Stock Spinoff Investing's 6, including screeners, data visualizations, and quant. Stock Spinoff Investing counters by keeping things simpler.

Key differences at a glance

Real-time data
Portfolio123
Cheaper paid plan
Portfolio123$25/mo vs $58.08/mo
Broader coverage
Portfolio12319 vs 6 categories
Desktop app
Portfolio123
API access
Portfolio123
Asset coverage
Portfolio123Adds ETFs and closed-end funds
See the full side-by-side table
Portfolio123 logo

Choose

Portfolio123 if…

  • Delayed quotes won't cut it; you need real-time data
  • You want the cheaper way in: plans start at $25/mo instead of $58.08/mo
  • You want an API so you can script or automate things
  • You care about screeners, data visualizations, and quant, things Stock Spinoff Investing doesn't offer
Stock Spinoff Investing logo

Choose

Stock Spinoff Investing if…

  • You care about calendar, corporate actions & special situations, and newsletters, things Portfolio123 doesn't offer

Comparison snapshot

Side-by-side comparison of Portfolio123 and Stock Spinoff Investing
Attribute
Portfolio123 logo
Portfolio123
Stock Spinoff Investing logo
Stock Spinoff Investing
Pricing & plans
Starting price
Free • From $25/moFree • From $58.08/mo
Free tier
YesYes
Free trial
Plan limits
Free Screener & Backtesting Access: duration days: 30
Platforms & access
Web app
YesYes
Desktop app
YesNo
Mobile app
NoNo
API access
YesNo
Broker sync
Yes
Integrations
Interactive Brokers and TradierDiscord and Memberful
Audience & fit
Experience level
Beginner, Intermediate, AdvancedBeginner, Intermediate, Advanced
Best for
Retail Traders, Pro Retail +5 more
Categories covered
196
Regions
North America, EuropeNorth America, Europe, APAC
Data & capabilities
Data quality
5 signals: Latency: Real-time and End of Day, Granularity: EOD +3 more3 signals: Latency: End of Day, Granularity: EOD +1 more
Data partners
4 partners: FactSet, S&P Global Market Intelligence +2 more
Capabilities
6 signals: Custom formulas, Ranking backtests +4 more
Try itVisit Portfolio123Visit Stock Spinoff Investing

Standout features

Portfolio123 logo

What Portfolio123 does best

  1. 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.
  2. 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.
  3. 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.
  4. AI Factor lets users train machine‑learning predictors for expected returns and plug the predictions into ranking systems, strategy simulations and asset-level analysis, with no-code model evaluation, blocked K-fold cross validation, lift charts and model/portfolio statistics.
  5. Homepage currently advertises 30 days of free screener and backtesting access with no credit card required, in addition to the free Manage module.
Stock Spinoff Investing logo

What Stock Spinoff Investing does best

  1. Spin-off Calendar: Upcoming table with parent/spinco, tickers, target timing, first-trade date, and resource links; plus a Completed table with first-day price, current price, and return since spin-off.
  2. Premium research: roughly 1 new idea per month with detailed write-ups, weekly email updates, and a live monthly video Q&A.
  3. Community: members-only Discord for discussion and Q&A with the author.
  4. Special situations occasionally covered, including odd-lot split-off and tender/reverse-split trades.
  5. Subscribers receive access to historical newsletters; the first newsletter was issued in July 2018.

Data & access details

Attribute
Portfolio123 logo
Portfolio123
Stock Spinoff Investing logo
Stock Spinoff Investing
Coverage & fit
Asset types
StocksETFsClosed-End Funds
Stocks
Experience
BeginnerIntermediateAdvanced
BeginnerIntermediateAdvanced
Target audience
Retail TradersPro RetailInstitutional InvestorsAnalystsQuants/DevelopersFinancial AdvisorsStudents/Researchers
Not specified
Regions
North AmericaEurope
North AmericaEuropeAPAC
Coverage details
Countries: US and CAIdentifiers: Ticker
6 exchangesIdentifiers: Ticker
Data
Data freshness
Real-timeEnd of Day
End of Day
Data granularity
EOD
EOD
Data partners
FactSetS&P Global Market IntelligenceICE Data ServicesFRED
Not specified
Access & integrations
API protocols
REST
Not specified
API auth & delivery
Auth: APIKeySDKs: PythonDocs
Not specified
Import methods
BrokerOAuthCSV
Not specified
Integrations
Interactive BrokersTradier
DiscordMemberful
Export formats
CSVJSON
Not specified
Plans & trust
Capability signals
Custom formulasRanking backtestsUniverse builderBroker syncRebalancingCorrelation
Not specified
Vendor & support
Portfolio123Support: Forum
Stock Spinoff Investing (operated by Rich Howe, CFA)Country: USFounded 2018Support: Email
Curation ratings
Not specified
Methodology 3/5Reliability 3/5UX 3/5

Green tags are exclusive to that tool in this comparison.

Pricing breakdown

Portfolio123 logo
Portfolio123

$25/mo

Lower starting price

Free tierYes
Free trial

Plans & pricing

Manage (Free)Free
Free Screener & Backtesting AccessFree
  • duration days: 30
Retail Research Plans$25/mo
Professional / API & Data LicensesContact sales
Research Trial$19 per unit
Stock Spinoff Investing logo
Stock Spinoff Investing

$58.08/mo

Starting price

Free tierYes
Free trial

Plans & pricing

SSI Premium (Monthly)$97/mo
SSI Premium (Annual)$58.08/mo
Public Calendars (Free)Free

Coverage overlap

Shared categories

3

Where the two tools cover the same ground.

Community category leaders

ScreenersNo leader yet
Stock IdeasNo leader yet
PortfolioNo leader yet
WatchlistNo leader yet
BacktestingNo leader yet
FinancialsNo leader yet
Data VisualizationsNo leader yet
Valuation ModelsNo leader yet
AI ResearchNo leader yet
APIs & Data FeedsNo leader yet
BlogsNo leader yet
Broker ConnectorsNo leader yet
CalendarNo leader yet
CorrelationNo leader yet
EducationNo leader yet
Factor ExposureNo leader yet
Macro DataNo leader yet
NewslettersNo leader yet
QuantNo leader yet
ScoresNo leader yet
VideosNo leader yet
Browse the #1 tool in 90+ categories

Vote sentiment comparison

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Frequently Asked Questions

What's the difference between Portfolio123 and Stock Spinoff Investing?

Portfolio123 leans toward screeners, data visualizations, and quant, while Stock Spinoff Investing puts more weight on stock ideas, calendar, and corporate actions & special situations. They overlap in 3 categories, so for most people it comes down to workflow preference and price.

How much do Portfolio123 and Stock Spinoff Investing cost?

Good news: both Portfolio123 and Stock Spinoff Investing have free plans, so you can run them side by side and only pay if you hit a wall.

Does Portfolio123 or Stock Spinoff Investing have an API?

Portfolio123 has an API for programmatic access and custom integrations. Stock Spinoff Investing doesn't, so you're working through its interface.

Should I choose Portfolio123 or Stock Spinoff Investing?

It depends on what you're after. Pick Portfolio123 if screeners and data visualizations matter to you; go with Stock Spinoff Investing if you'd rather have calendar and corporate actions & special situations. And if you only need the basics both share, let price decide.

What asset classes do Portfolio123 and Stock Spinoff Investing cover?

Both cover stocks. Portfolio123 also handles ETFs and closed-end funds.

Does Portfolio123 or Stock Spinoff Investing have real-time data?

Portfolio123 offers real-time data, which matters if you trade actively. Stock Spinoff Investing runs on delayed or end-of-day data, which is perfectly fine for longer-term investors who don't live and die by the tick.

Can I export data from Portfolio123 and Stock Spinoff Investing?

Portfolio123 exports to CSV. Stock Spinoff Investing is stingier about getting data out.

Which has a better stock screener: Portfolio123 or Stock Spinoff Investing?

Portfolio123 has a stock screener for surfacing ideas; Stock Spinoff Investing doesn't, and focuses its energy elsewhere.

Can I track my portfolio with Portfolio123 or Stock Spinoff Investing?

Portfolio123 handles portfolio tracking. Stock Spinoff Investing is really a research tool; you'd track your portfolio elsewhere.

Top 50 Investing ToolsSee where these two land in our community-voted ranking of the best investing tools.

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.