Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

Zenas BioPharma, Inc.

ZBIO · Nasdaq · CIK 0001953926 · Healthcare · Biotechnology

INSIDER SIGNAL

50.8 / 100

1 buyers · 3 purchase transaction lines · $2.1M gross purchase

WHY THIS SIGNAL?

Buyer breadthLow
Purchase sizeModerate
RoleModerate
RecencyLow
ConvictionStrong
Score anatomy

Each bar shows the contribution to the current score; the weights and formula stay unchanged.

Cluster+7.0 / 35
Purchase size+20.0 / 25
Role+13.0 / 20
Recency+0.8 / 10
Conviction+10.0 / 10

What is holding the score back?

  • ⚠ Cluster breadth is moderate · 1 insider(s), not 4+
  • ⚠ Role scores low · most senior buyer: Chief Executive Officer (CEO, chair and 10% owners score lowest)
  • ⚠ Purchase activity is becoming less recent

Purchase-size comments are relative to the model scale. Average daily volume is a separate market-context diagnostic.

US-v1.2 ranks qualifying equity purchases under the current 180-day rules. The score is a research priority, not a return forecast or probability. Backtests have not shown that a higher US score is followed by better returns.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
MOULDER LEON O JRChief Executive Officer
●●●
● Purchase▼ Sale○ Other

—

Purchase breadth & concentration

QUALIFYING BUYERS1
PURCHASE CONCENTRATION100%Largest buyer: MOULDER LEON O JR · $2.1M
CLUSTER BUYING · 15D1 insiderPeak activity: 2026-04-28–2026-04-29

Roles in the peak window: Chief Executive Officer. Concentration uses priced qualifying P lines only and does not change the saved score.

SIGNAL HISTORY

50.8 / 100

Latest recorded score

→ +0.0 ptsversus the previous recorded snapshot
  1. 50.9
  2. 50.9
  3. 50.9
  4. 50.8
  5. 50.8

Only scores saved when a full US scoring run completed are shown; gaps are not reconstructed.

Recent Form 4 activity

15Purchases
0Sales
0Other Form 4 lines
8SEC filings · 365 days
BUYING3 qualifying P line(s) · 180 days
SELLING0 sale line(s) · context only
OTHER0 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context provides additional background on recent price performance and risk. It does not affect the Insider Signal.

Price performance

1M
-12.3%
3M
-2.2%
6M
+33.4%
12M
+5.3%

Volatility & liquidity

Volatility
104.0%
Beta
—
Avg daily value
USD 19.7M

Valuation

Market cap
USD 1.8B
P/E
—

Fundamentals

Profit margin
—
ROE
-156.0%
Industry
Biotechnology

Market data

Price data up to: 2026-10-11 · Price source: OpenBB/yfinance; volume from price cache (yfinance) · From SEC filings: Market cap, ROE · Fiscal year ended: 2025-12-31 · Market cap is the shares outstanding stated on the filing cover multiplied by the latest close. Share count date: 2026-07-31 · Status: PASS

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
11,941,601
Previous report
11,871,346
Avg daily volume
771,653
Days to cover
15.5

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2026-05-18MOULDER LEON O JRPurchase (P)Common Stock60,000USD 16.88USD 1,012,800SEC filing ↗
2026-04-29MOULDER LEON O JRPurchase (P)Common Stock35,000USD 17.62USD 616,700SEC filing ↗
2026-04-28MOULDER LEON O JRPurchase (P)Common Stock25,000USD 18.02USD 450,500SEC filing ↗
2026-03-31MOULDER LEON O JRPurchase (P)Common Stock34,000USD 19.31USD 656,540SEC filing ↗
2026-03-31Lu HongboPurchase (P)Common Stock75,000USD 20.00USD 1,500,000SEC filing ↗
2026-03-30MOULDER LEON O JRPurchase (P)Common Stock20,000USD 18.23USD 364,600SEC filing ↗
2026-02-13Allen Patricia LPurchase (P)Common Stock4,160USD 26.36USD 109,658SEC filing ↗
2026-02-12Allen Patricia LPurchase (P)Common Stock15,700USD 24.85USD 390,088SEC filing ↗
2026-02-11Lu HongboPurchase (P)Common Stock25,985USD 22.50USD 584,662SEC filing ↗
2026-02-02MOULDER LEON O JRPurchase (P)Common Stock57,000USD 17.96USD 1,023,720SEC filing ↗
2026-01-09MOULDER LEON O JRPurchase (P)Common Stock20,000USD 16.55USD 331,000SEC filing ↗
2026-01-08MOULDER LEON O JRPurchase (P)Common Stock30,000USD 16.30USD 489,000SEC filing ↗
2026-01-07MOULDER LEON O JRPurchase (P)Common Stock50,000USD 16.38USD 819,000SEC filing ↗
2025-10-09Nunn Jason RaleighPurchase (P)Common Stock63,158USD 19.00USD 1,200,002SEC filing ↗
2025-10-09George Simeon; SR ONE CAPITAL MANAGEMENT, LLCPurchase (P)Common Stock126,315USD 19.00USD 2,399,985SEC filing ↗

Form 4 evidence

15 transaction lines in the latest 365-day window; 71 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-05-18MOULDER LEON O JRPurchase (P)Common Stock60,000USD 16.88USD 1,012,800SEC filing ↗
2026-04-29MOULDER LEON O JRPurchase (P)Common Stock35,000USD 17.62USD 616,700SEC filing ↗
2026-04-28MOULDER LEON O JRPurchase (P)Common Stock25,000USD 18.02USD 450,500SEC filing ↗
Show recent Form 4 evidence (13 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-05-18MOULDER LEON O JRPurchase (P)Common Stock60,000USD 16.88USD 1,012,800SEC filing ↗
2026-04-29MOULDER LEON O JRPurchase (P)Common Stock35,000USD 17.62USD 616,700SEC filing ↗
2026-04-28MOULDER LEON O JRPurchase (P)Common Stock25,000USD 18.02USD 450,500SEC filing ↗
2026-03-31MOULDER LEON O JRPurchase (P)Common Stock34,000USD 19.31USD 656,540SEC filing ↗
2026-03-31Lu HongboPurchase (P)Common Stock75,000USD 20.00USD 1,500,000SEC filing ↗
2026-03-30MOULDER LEON O JRPurchase (P)Common Stock20,000USD 18.23USD 364,600SEC filing ↗
2026-02-13Allen Patricia LPurchase (P)Common Stock4,160USD 26.36USD 109,658SEC filing ↗
2026-02-12Allen Patricia LPurchase (P)Common Stock15,700USD 24.85USD 390,088SEC filing ↗
2026-02-11Lu HongboPurchase (P)Common Stock25,985USD 22.50USD 584,662SEC filing ↗
2026-02-02MOULDER LEON O JRPurchase (P)Common Stock57,000USD 17.96USD 1,023,720SEC filing ↗
2026-01-09MOULDER LEON O JRPurchase (P)Common Stock20,000USD 16.55USD 331,000SEC filing ↗
2026-01-08MOULDER LEON O JRPurchase (P)Common Stock30,000USD 16.30USD 489,000SEC filing ↗
2026-01-07MOULDER LEON O JRPurchase (P)Common Stock50,000USD 16.38USD 819,000SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerZBIO
CIK0001953926
SectorHealthcare
IndustryBiotechnology Yahoo Finance
SEC SIC2834 Pharmaceutical Preparations
ExchangeNasdaq

Data coverage

Local Form 4 history71 transaction lines from 2024-09-13 to 2026-05-18
43 P purchase lines · 0 S sale lines · 28 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.