Top Whale Tickers in Mid-September 2026: Dell, Seagate, and Chime Lead Insider Flow

Top whale tickers in mid-September 2026 look very different from the early-month board. Through September 20, 2026, ProBors whale leaderboards show DELL (Dell Technologies) at 615 whale-class prints in 14 days—more than triple CRWD (CrowdStrike) at 79—while STX (Seagate) ranks second by frequency with about $212 million in net reported value. CHYM (Chime Financial) is a new entrant near the top by dollar volume, with DST Global fund sales totaling tens of millions after the IPO lock-up window. This guide maps the mid-September leaderboard, a five-step triage framework, recent large Form 4 filings worth a second look, and what leaderboard volume does not prove. It is research context, not investment advice.

Why the mid-September whale board shifted from early September

Whale activity is a leaderboard of large Form 4 prints ranked by frequency and reported value—not a sentiment index. Three shifts stand out in the current window compared to the board as of September 6:

• Dell replaced CrowdStrike at the top of the 14-day print-count board. DELL shows 615 whale-class rows and 549 open-market sales with zero purchases, while CRWD dropped to 79 prints (down from 122 in early September). Most DELL volume still comes from Silver Lake-affiliated fund entities filing multi-line distributions—not a single officer headline sale.
• Seagate climbed to #2 by frequency and reported value. STX carries 124 prints and about −$212 million in net reported value, driven by officer sales like EVP Morris John Christopher's $11.9 million code S row filed September 16, 2026.
• Chime is new to the top ten by dollar volume. CHYM shows 57 prints and about −$169 million in net reported value, with DST Global Advisors Ltd filing a $47.1 million open-market sale on September 14, 2026 (filed September 16).

A ticker with triple-digit prints and zero buys tells a different research story than a post-IPO name with concentrated fund-holder distribution. Start with the board, then drill into transaction codes and individual rows.

14-day whale leaderboard (as of September 20, 2026)

The table below reflects ProBors whale activity over the last 14 days as of September 20, 2026. Print counts include large Form 4 rows indexed in the platform; net reported value sums directionally (sales show as negative).

Over 30 days, DELL still leads by print count (878 rows, zero buys, about −$762.7 million in net reported value), followed by STX (223 prints, about −$281.3 million) and CRWD (212 prints). The 30-day view confirms sustained fund-holder distribution on DELL and officer selling on storage names—not a one-week spike tied to a single earnings date.

Note on mixed codes: ATAI and EBAY can show large net values with low code S counts in the buy/sell split because disposition (D), conversion, and other Form 4 codes also flow through whale feeds. Always open the underlying filing before treating a leaderboard rank as a bearish signal.

A five-step triage framework for loud whale tickers

Use the same checklist when a ticker tops the mid-September board so tax withholding rows and fund distributions do not masquerade as discretionary flow.

1. Confirm the SEC transaction code

Open-market sales use code S; open-market purchases use code P. Grants (A), dispositions (D), conversions (C), and option exercises (M, X) are different economic events. ProBors shows the code and trade type on each whale row—filter here before reacting to dollar size.

2. Separate fund-holder waves from officer sales

DELL illustrates why this matters: Silver Lake-affiliated entities file dozens of code S lines on the same trade dates, often split across multiple tranches under $3 million each. A single officer sale on STX or NVDA reads differently than a PE-holder distribution program spanning hundreds of rows.

3. Measure filing lag in calendar days

Form 4 is generally due within two business days after the transaction. A one-day lag on a September 17 trade filed September 18 is routine. A four-day gap on a large sale deserves a footnote read on SEC EDGAR.

4. Read signal scores as a sort key—not a verdict

ProBors signal scores weigh size, role, timing, and pattern history. A score of 10 on an NVDA officer sale flags attention but does not prove bearish intent—it may reflect size and role on a name with a long selling history. A score of 0 on a Blackstone sale can still be economically meaningful; it often means the row matches that insider's typical pattern. Sort by signal after filtering codes. For scoring details, see how ProBors trade signal scores work.

5. Cross-check chart and congressional context

Open the ticker workspace on ProBors: review price reaction since the trade date, any congressional markers, and whether the AI summary flags earnings or lock-up events. Whale flow plus politician activity on the same name is a stronger research prompt than either feed alone.

Recent filings worth a second look

The table below shows deduplicated whale rows from ProBors as of September 20, 2026, filed in mid-September. Values are as reported in the platform; lag is calendar days between trade date and filing date.

How to read this snapshot without overfitting:

• NVDA Stevens Mark A filed multiple code S lines in early September totaling well over $200 million across the week; the row above is the largest same-day print. High signal scores reflect size and officer role on a mega-cap with active selling cadence—not a fresh catalyst.
• CHYM DST Global Advisors Ltd filed a $47.1 million sale two days after the September 14 trade date—classic post-IPO fund distribution, not a single officer discretionary exit. Officer James Feuille also filed multi-million-dollar sales the same week.
• STX Morris John Christopher's $11.9 million sale pairs with exercise rows on the same filing—read the full Form 4 before treating it as a standalone open-market exit.
• TEM Lefkofsky Eric P filed six code S lines on September 17 totaling about $16.1 million; the table shows the largest single print with a one-day filing lag.
• BX Baratta Joseph's same-day $7.2 million sale scores 0 because it matches his historical pattern—size alone does not elevate the row.
• DELL Silver Lake entities filed dozens of code S lines on September 16 filed September 18; the row above is one tranche in a sustained distribution wave that explains DELL's #1 leaderboard rank.

How to research whale tickers on ProBors

1. Open the Whales tab from the dashboard and sort by filing date (newest first).
2. Click Top tickers and toggle between 14-day and 30-day windows to see whether flow is sustained or spiking.
3. Filter by ticker when a name like DELL or CHYM hits your watchlist.
4. Open a row to read transaction code, insider title, signal score, and footnote context.
5. Jump to the Market workspace for the same ticker to overlay price action and congressional markers.
6. Add tickers with recurring whale prints to a watchlist if you want alerts on the next filing—not on live price.

For tab navigation details, see the ProBors Whales tab guide. For the full triage checklist, see how to triage whale transactions on ProBors.

What this whale data does not prove

A sell-heavy whale leaderboard does not prove:

• That insiders traded on material non-public information
• That a ticker will fall because officers sold shares or funds distributed holdings
• Exact share counts or post-trade holdings (Form 4 value fields are as reported, not always full position snapshots)
• That every code S row is discretionary—many reflect 10b5-1 plans, tax events, or PE rebalancing
• That zero buys on a leaderboard ticker means no insider interest (smaller purchases below whale thresholds may exist elsewhere in Form 4 data)
• That fund-holder distribution on DELL or CHYM equals bearish management sentiment—it may reflect lock-up expirations, LP liquidity, or planned secondary activity

Insider selling and fund distribution is often routine. The research value is prioritization: which tickers deserve a footnote read, a chart check, and a second pass against the original SEC filing.

FAQ

What counts as a "whale" transaction on ProBors?

ProBors surfaces large Form 4 filings that meet size thresholds for the Whales feed—typically high-dollar open-market prints and other reportable rows that stand out from routine compensation activity. The exact cutoff is applied during ingestion; use transaction code and reported value together, not size alone.

Why did DELL replace CRWD at the top of the whale board?

DELL shows 615 whale-class prints in 14 days through September 20, 2026, compared with 79 on CRWD. Silver Lake-affiliated entities file dozens of code S lines per week, inflating print count relative to single-issuer officer sales. CRWD remains active on the 30-day board (212 prints) but no longer leads the shorter window.

Why does CHYM rank high with only 57 prints?

CHYM carries about −$169 million in net reported value on 57 prints because post-IPO fund sales like DST Global's $47.1 million row are large per line. Frequency and dollar volume measure different things—rank by the metric that matches your research question.

How is mid-September different from early September on the whale board?

Early September leaderboards were led by CRWD and CRNX; mid-September shows DELL and STX at the top with CHYM and ATAI entering the top ten. CRWD and SE remain active but rank lower by print count. The overall sell-heavy shape persists; the specific names rotating through the top ten are what changed.

Should I short a stock because it tops the whale leaderboard?

No. Leaderboard volume is a research queue, not a trading signal. Verify each row on EDGAR, read footnotes for 10b5-1 plans, and treat the data as disclosure context. This is research context, not investment advice.

How often does ProBors refresh whale data?

Form 4 ingestion runs on a regular schedule. Check probors.com/status for the latest SEC Form 4 / Whales source health before citing rows in notes or publications.

Track whale flow on ProBors

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Related reading

• Top whale tickers in September 2026 (early month)
• Dell whale insider sales explained
• How to triage whale transactions on ProBors
• Insider buying clusters: what to look for
• Why insider selling is usually not a signal

Sources

• SEC Form 4 overview — reporting requirements for insiders
• SEC EDGAR search — verify individual Form 4 filings
• SEC investor bulletin: Forms 3, 4, and 5
• Rows were checked in ProBors and should be verified against the original filing.
• Ingestion health: probors.com/status