SEC Form 4
Moleculin Biotech, Inc. (MBRX) insider trading
In the 12 months to Oct 26, 2026, 3 MBRX insiders reported open-market purchases of $0 across 3 filings; no open-market sales were filed.
Latest filing · Last 12 months · Source: SEC EDGAR · How we count
- Open-market sales
- $0
- 0 filings · 0 insiders
- Open-market purchases
- $0
- 3 filings
$ excludes 3 trades without a price.
Who traded MBRX, and when
- Purchase
MBRX daily close from Oct 27, 2025 to Oct 26, 2026, between $5.30 and $259.85, last $6.99. 0 sale and 3 purchase filings by 3 insiders, marked at their filing dates. Donald H. Picker, Chief Science Officer: across 1 filing, first filed Aug 5, 2026, last Aug 5, 2026. Jonathan P. Foster, Chief Financial Officer: across 1 filing, first filed Aug 5, 2026, last Aug 5, 2026. Walter V. Klemp, CEO and President: across 1 filing, first filed Aug 5, 2026, last Aug 5, 2026.
Largest mark · tap a row for others
Donald H. Picker · Chief Science Officer
Purchase unpriced
173,333 shares
Filed Aug 5, 2026 · traded Aug 3
Close on filing date $7.80
Donald H. Picker · Chief Science Officer
Chief Science Officer
Jonathan P. Foster · Chief Financial Officer
Chief Financial Officer
Walter V. Klemp · CEO and President
CEO and President
Open-market trades
3 filings in the last 12 months| Insider | Role | Sold | Bought | Filings | Pre-arranged (10b5-1) | Last filed |
|---|---|---|---|---|---|---|
| Donald H. Picker | Chief Science Officer | — | — | 1 | — | |
| Jonathan P. Foster | Chief Financial Officer | — | — | 1 | — | |
| Walter V. Klemp | CEO and President | — | — | 1 | — |
| Filed | Insider | Type | Shares | Avg price | Value | Held after | Source |
|---|---|---|---|---|---|---|---|
traded | Donald H. Picker Chief Science Officer | Purchase | 173,333 | — | — | 174,086 | |
traded | Walter V. Klemp CEO and President | Purchase | 533,333 | — | — | 564,340 | |
traded | Jonathan P. Foster Chief Financial Officer | Purchase | 293,333 | — | — | 305,673 |
GET /stocks/filings/vX/form-4?tickers=MBRX&filing_date.gte=2025-10-26&sort=filing_date.desc&limit=500{
"status": "OK",
"results": [
{
"tickers": [
"MBRX"
],
"issuer_cik": "0001659617",
"owner_cik": "0000938419",
"accession_number": "0001437749-26-025928",
"form_type": "4",
"filing_date": "2026-08-05",
"period_of_report": "2026-08-03",
"issuer_name": "Moleculin Biotech, Inc.",
"issuer_trading_symbol": "MBRX",
"owner_name": "KLEMP WALTER V",
"is_director": true,
"is_officer": true,
"officer_title": "CEO and President",
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": false,
"transaction_date": "2026-08-03",
"transaction_code": "P",
"equity_swap_involved": false,
"transaction_shares": 533333,
"transaction_acquired_disposed": "A",
"shares_owned_following_transaction": 564340,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "On August 3, 2026, the reporting person acquired 533,333 shares of common stock and Series I warrants to purchase 1,599,999 shares of common stock at a combined purchase price of $0.75 per one share of common stock and three accompanying warrants in a public offering."
}
]
},
{
"tickers": [
"MBRX"
],
"issuer_cik": "0001659617",
"owner_cik": "0001266800",
"accession_number": "0001437749-26-025927",
"form_type": "4",
"filing_date": "2026-08-05",
"period_of_report": "2026-08-03",
"issuer_name": "Moleculin Biotech, Inc.",
"issuer_trading_symbol": "MBRX",
"owner_name": "PICKER DONALD H",
"is_officer": true,
"officer_title": "Chief Science Officer",
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": false,
"transaction_date": "2026-08-03",
"transaction_code": "P",
"equity_swap_involved": false,
"transaction_shares": 173333,
"transaction_acquired_disposed": "A",
"shares_owned_following_transaction": 174086,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "On August 3, 2026, The reporting person acquired 173,333 shares of common stock and Series I warrants to purchase 519,999 shares of common stock at a combined purchase price of $0.75 per one share of common stock and three accompanying warrants in a public offering."
}
]
}
]
}
// trimmed to 2 resultsThe response includes every Form 4 record; this page keeps open-market purchases and sales on common stock and removes duplicate joint-filer rows.
Other insider activity (not market trades) · 22 records
- Option exercises12 records
- Tax withholding10 records
Reported on Form 4 but not purchases or sales in the market, so not counted in the totals above.
How to read this page
- Open-market purchase or sale
- A buy or sell of the company's stock at market price. Grants, option exercises, shares withheld for tax, gifts and employee stock plan purchases are listed separately and not counted.
- Filing date
- Insiders have two business days to report a trade. Totals and the chart use the filing date, when the trade became public.
Frequently asked questions
Has Moleculin Biotech, Inc.'s CEO sold stock?
No. Walter V. Klemp (CEO) made no open-market sales filed as CEO in the last 12 months.
How current is MBRX’s insider data?
These are MBRX Form 4 filings from the last year, refreshed daily. The Massive Form 4 API has the full, continuously updated record.
What counts as an open-market buy or sell?
Only purchases and sales at the market price. Option exercises, grants, gifts, and shares withheld for taxes are reported on Form 4 but are left out of the buy and sell totals.
Build with AI
Track MBRX insider trades with your agent
This page joins two Massive endpoints: Form 4 filings and daily prices. Ask an agent to watch for new filings:
Using the Massive API (massive.com/docs/llms.txt), check Form 4 filings for MBRX every day with transaction_code=P and tell me when an insider files an open-market purchase, with their role, shares, price and the filing link.
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