A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 7 filings in this group are Form 4s for X4 Pharmaceuticals, Inc.
The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.
Across the 7 insider filings shown, the breakdown is 5 open-market sale and 2 compensation award. 5 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.
Form 4
Open-market sale
Insider Selling
2026-10-05
XFOR insider KIRSKE DAVID (Chief Financial Officer) sold 11,767 shares (~$33.7K)
KIRSKE DAVID, listed as Chief Financial Officer at X4 Pharmaceuticals, Inc, reported an open-market sale of 11,767 XFOR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
S |
Open-market sale
|
11,767 |
$2.86 |
$33.7K |
Filing: Form 4 (Insider Transaction)
Insider: KIRSKE DAVID (Chief Financial Officer)
Shares: 11,767
Est. Value: $33.7K
Form 4
Open-market sale
Insider Selling
2026-08-13
XFOR insider Volpone John (President) sold 24,576 shares (~$109.2K)
Volpone John, listed as President at X4 Pharmaceuticals, Inc, reported an open-market sale of 24,576 XFOR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
S |
Open-market sale
|
24,576 |
$4.44 |
$109.2K |
Filing: Form 4 (Insider Transaction)
Insider: Volpone John (President)
Shares: 24,576
Est. Value: $109.2K
Form 4
Open-market sale
Insider Selling
2026-08-13
XFOR insider Craig Adam R (Director, Executive Chairman) sold 47,436 shares (~$210.8K)
Craig Adam R, listed as Director, Executive Chairman at X4 Pharmaceuticals, Inc, reported an open-market sale of 47,436 XFOR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
S |
Open-market sale
|
47,436 |
$4.44 |
$210.8K |
Filing: Form 4 (Insider Transaction)
Insider: Craig Adam R (Director, Executive Chairman)
Shares: 47,436
Est. Value: $210.8K
Form 4
Open-market sale
Insider Selling
2026-07-01
XFOR insider KIRSKE DAVID (Chief Financial Officer) sold 8,543 shares (~$36.4K)
KIRSKE DAVID, listed as Chief Financial Officer at X4 Pharmaceuticals, Inc, reported an open-market sale of 8,543 XFOR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
S |
Open-market sale
|
8,543 |
$4.26 |
$36.4K |
Filing: Form 4 (Insider Transaction)
Insider: KIRSKE DAVID (Chief Financial Officer)
Shares: 8,543
Est. Value: $36.4K
Form 4
Compensation award
Tax / Compensation Filing
2026-07-01
XFOR insider Form 4 filed for equity award, exercise, or tax withholding
Gold Kelly (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.
Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
A |
Compensation award
derivative · Stock Option (right to buy)
|
110,000 |
— |
— |
Filing: Form 4 (Insider Transaction)
Insider: Gold Kelly (Director)
Form 4
Open-market sale
Insider Selling
2026-05-13
XFOR insider KIRSKE DAVID (Chief Financial Officer) sold 16,961 shares (~$72.8K)
KIRSKE DAVID, listed as Chief Financial Officer at X4 Pharmaceuticals, Inc, reported an open-market sale of 16,961 XFOR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
S |
Open-market sale
|
16,961 |
$4.29 |
$72.8K |
Filing: Form 4 (Insider Transaction)
Insider: KIRSKE DAVID (Chief Financial Officer)
Shares: 16,961
Est. Value: $72.8K
Form 4
Compensation award
Tax / Compensation Filing
2026-01-07
XFOR insider Form 4 filed for equity award, exercise, or tax withholding
Bridger Gary (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.
Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.
Transactions reported on this filing
| Code |
Nature |
Shares |
Price |
Value |
A |
Compensation award
derivative · Stock Option (right to buy)
|
110,000 |
— |
— |
Filing: Form 4 (Insider Transaction)
Insider: Bridger Gary (Director)