Today's Substack newsletters: Sept 26, 2026

Steve Kim's Korean Cosell newsletter jumps to number 1 on Substack Trending for September 26, 2026, while AI Investment Brief by Exponential View debuts at rank 2. Martini Mondays plunges from yesterday's top slot to rank 9, a swing of eight positions in one day. The board froze at 2026-09-26T08:01:41.476382 with three first-time top-10 names and three September 25 titles dropping off entirely.

Steve Kim Korean Cosell: Sales strategist Steve Kim's Korean Cosell letter leads after rising from rank 3 on September 25. No widely reported trigger identified for September 26, 2026.
AI Investment Brief by Exponential View: Exponential View's new AI Investment Brief enters at rank 2, covering venture and public markets around artificial intelligence. No widely reported trigger identified for September 26, 2026.
Mindful Equestrian Club: The equestrian mindfulness newsletter climbs from rank 5 to rank 3. No widely reported trigger identified for September 26, 2026.
Intentional Luxury Bish: A luxury lifestyle letter slips from rank 2 to rank 4 while staying on the board. No widely reported trigger identified for September 26, 2026.
Solo Millions: Solo Millions debuts at rank 5 as a new entrant focused on solo founder revenue stories. No widely reported trigger identified for September 26, 2026.
Vanessa's Stitch Club: Vanessa's Stitch Club sewing community letter enters at rank 6. No widely reported trigger identified for September 26, 2026.
Paige Paul: Paige Paul's personal newsletter falls from rank 4 to rank 7. No widely reported trigger identified for September 26, 2026.
The Pyramid and the Pool with Martha Beck: Martha Beck's Pyramid and the Pool series holds near rank 8 after ranking 9 on September 25. No widely reported trigger identified for September 26, 2026.
Martini Mondays: The cocktail culture letter drops from rank 1 to rank 9, the largest single-day slide on this board. No widely reported trigger identified for September 26, 2026.
Seedy19 Biotech Investing: Seedy19's biotech investing coverage slides from rank 6 to rank 10. No widely reported trigger identified for September 26, 2026.

The live ranked board beyond today's top 10 is available via the Trends MCP API. Get your free API key

What changed on Substack since yesterday

September 25 ranked Martini Mondays first, followed by Intentional Luxury Bish, Steve Kim, Paige Paul, Mindful Equestrian Club, Seedy19, Jake's Take, RiffPost, Pyramid and Martha Beck, and Michael Lombardi. September 26 drops Jake's Take, RiffPost, and Michael Lombardi while adding AI Investment Brief, Solo Millions, and Vanessa's Stitch Club. Movers include Steve Kim up 2 slots, Mindful Equestrian up 2, Paige Paul down 3, Seedy19 down 4, and Martini Mondays down 8.

What today's Substack trends reveal

Business and investing letters crowd the middle ranks, while lifestyle titles trade places at the extremes. The AI Investment Brief entrance at rank 2 suggests readers chase macro AI finance explainers even when no single press event maps to the date. Publishers tracking share-of-voice can poll the Substack Trending API and compare scheduling stacks against Later alternatives for cross-posting.

Track these trends in real time with Trends MCP

Substack ranks update daily; pairing them with open rates from your own ESP still requires first-party data, but the leaderboard shows which public newsletters gain discovery momentum.