About This Site
Inverting The Traditional Media Model
MarketStack's editorial layer is driven by one signal: paid readership momentum on Finance Substack. Every post surfaces because its author has earned it in the market — not because an editor chose it.
The MarketStack Index is an algorithmic score — no editorial discretion, no manual curation. An author ranks where the data puts them.
The site follows a three-tier model:
1. The MarketStack Index (MSI) — the composite top-100 ranking of authors scored on Mass (durability in Substack's Bestsellers Top 100) and Velocity (recency of growth in Substack's Rising Top 100).
2. Author Signals — authors showing unusual movement today: significant rank jumps, personal bests, or returns after a long absence.
3. Rising Rank — authors currently on the Substack Rising in Finance list who fall outside the Index and Signals.
Authors are tagged accordingly, for instance: MSI #5 Signals Rising #2
Paid Readerships
Readers fund writers directly on Substack. Every subscription is a signal.
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The MarketStack Index
Composite of Mass (Bestsellers durability) and Velocity (Rising emergence). Author signals & authors rising daily.
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Editorial Feed
Latest posts from the highest-ranked authors, live. No editor required.
The paid-subscriber-driven editorial model
Topic categories are generated dynamically from the pool of active posts, which rebuild twice daily and reach back up to three days.
The hero story on the Front Page tab is selected algorithmically each build, scored across four factors:
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Authority
Index rank of the author
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30
Narrative
Multiple authors on the same theme
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20
Recency
Fades to zero after 12 hours
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10
Title
Depth of headline
Scored out of 100 — highest score becomes the lead story, refreshed with every site rebuild
Narrative Physics · Quantifying readership momentum
The MarketStack Index
The Substack Rising list measures speed. The Substack Bestsellers list measures weight. The MarketStack Index combines them into momentum — and in physics, as on Substack, momentum is the product of mass and velocity.
The MarketStack Index is a composite measure of sustained reader attention in the Finance Substack ecosystem. The Index Score weights Mass (durability of paid readership) at 80% and Velocity (recency of growth) at 20%:
Index Score = Mass × 0.80 + Velocity × 0.20
Mass · Bestsellers durability
Durability of paid readership. An author's presence and rank in Substack's Bestsellers Top 100 over a 90-day rolling window, with exponential decay (τ = 30 days) so recent presence weighs more than old.
Velocity · Rising emergence
Recency of growth. An author's presence and rank in Substack's Rising Top 100 over a 42-day rolling window, with exponential decay (τ = 14 days) so recent rises dominate. Sorting by Velocity surfaces emerging voices before they harden into Bestsellers.
The published ranking is the composite top 100 by Index Score. Authors who land in the top 100 by Mass or Velocity but fall outside the composite top 100 are still listed below the Index 100 on the Terminal, so the ranking reads as a continuous gradient from durable Bestsellers through fast-rising emergent writers.
For a deeper, mathematical explanation of how Mass and Velocity are calculated, see the Index tab in the MarketStack Terminal →
Narrative Physics
Narratives compress complexity into a tradable frame. They coordinate the forces of attention, belief and positioning. Like gravitational fields, narratives shape behaviour from a distance. A strong narrative bends decisions. The field is strongest when the story is simple, emotionally legible, and attached to visible price action.
Markets don't prove what narratives are true. They prove what narratives are being adopted. Price is motion, not truth. And as Soros observed — adoption itself can feed further price moves, which then validate the story in a feedback loop. The story doesn't describe the market. It becomes the market.
This is where writers matter. Belief doesn't emerge from writers who spike attention. It emerges from writers who sustain attention.
Author Signals · Statistically unusual rank moves
Author Signals
When an author's rank moves in an unusual pattern.
On any given day, dozens of things are happening across the Rising list — rank spikes, first appearances, authors returning after long absences, voices outperforming their own historical average. Most of it passes unnoticed unless you're manually scanning the data. Signals does that scanning automatically.
Multiple signals compound. An author triggering three signals simultaneously scores higher than one triggering a single spike. The MarketStack Index rank acts as a credibility weight — a large spike from an established author with a long track record scores higher than the same spike from an unknown.
For a deeper explanation of how signals are calculated, see the Author Signals tab in the MarketStack Terminal →
Why this matters
The Rising list is a real-time signal of what the finance Substack community is reading and sharing. But the raw list doesn't tell you what's unusual — it just tells you the rankings. Signals translates the data into something actionable: here are the authors whose behaviour today is outside the normal range, and here's why.
It's the difference between watching a market and having a screen that flashes when something moves.