Was the Milestone Pharmaceuticals (MIST) CEO’s share sale part of a Rule 10b5-1 plan?

Yes. The sale was executed under a Rule 10b5-1 trading plan. A footnote states the plan was adopted by Joseph Oliveto in advance, meaning the timing and size of trades were pre-scheduled rather than based on day-to-day market decisions.

Milestone (MIST) CEO sells 36,500 shares under Rule 10b5-1 plan

Q: Does this Milestone Pharmaceuticals (MIST) Form 4 involve derivative securities or only common shares?

This Form 4 discloses a transaction only in common shares. The reported activity is a non-derivative open-market sale of 36,500 common shares, and the derivative section shows no remaining derivative positions in this specific filing excerpt.

Filing Impact

(Neutral)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

Milestone Pharmaceuticals President and CEO Joseph Oliveto sold 36,500 common shares of the company in an open-market transaction on April 16, 2026 at a weighted average price of $2.26 per share. The shares were sold in multiple trades between $2.25 and $2.28 per share.

The sale was made pursuant to a Rule 10b5-1 trading plan previously adopted by Oliveto, meaning the trades were pre-scheduled rather than discretionary. Following this transaction, he continues to hold 446,244 common shares directly.

Insider Trade Summary 10b5-1

Net Seller: 36,500 shares ($82,490)

Net Sell 1 txn

Insider Oliveto Joseph

Role President and CEO

Sold 36,500 shs ($82K)

Type	Security	Shares	Price	Value
Sale	Common Shares	36,500	$2.26	$82K

Holdings After Transaction: Common Shares — 446,244 shares (Direct, null)

Footnotes (1)

This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 30, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.25 to $2.28 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold each separate price within the range set forth in this footnote.

Key Figures

Shares sold: 36,500 shares Weighted average sale price: $2.26 per share Sale price range: $2.25–$2.28 per share +2 more

5 metrics

Shares sold 36,500 shares Open-market sale of common shares on April 16, 2026

Weighted average sale price $2.26 per share Average price for 36,500 common shares sold

Sale price range $2.25–$2.28 per share Range of individual trade prices in the sale

Shares held after transaction 446,244 shares Direct common share holdings following the sale

Net buy/sell shares -36,500 shares Net effect of reported transactions in this Form 4

Key Terms

Rule 10b5-1 trading plan, weighted average price, open-market sale, common shares

4 terms

Rule 10b5-1 trading plan regulatory

"This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

open-market sale financial

"transaction_action: open-market sale"

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

common shares financial

"security_title: Common Shares"

Common shares are the basic units of ownership in a company that give holders a claim on profits and a right to vote on key matters, like electing the board. Think of them as membership cards in a club: they let you share in successes and losses, but in a bankruptcy or liquidation they are paid after creditors and preferred shareholders, so their value can swing more and matters for assessing risk and potential return.

Form 4 Insider Transactions: What Each Field Means →

04/20/2026 - 04:06 PM

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Oliveto Joseph

(Last)

(First)

(Middle)

C/O MILESTONE PHARMACEUTICALS INC.

1111 DR. FREDERIK-PHILIPS BLVD, STE 420

(Street)

MONTREAL

H4M 2X6

(City)

(State)

(Zip)

QUEBEC, CANADA

(Country)

2. Issuer Name and Ticker or Trading Symbol
Milestone Pharmaceuticals Inc. [ MIST ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	President and CEO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/16/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Shares	04/16/2026		S⁽¹⁾		36,500	D	$2.26⁽²⁾	446,244	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 30, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.25 to $2.28 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold each separate price within the range set forth in this footnote.

	/s/ Joseph Oliveto	04/20/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What did Milestone Pharmaceuticals (MIST) CEO Joseph Oliveto report in this Form 4?

Joseph Oliveto reported an open-market sale of 36,500 common shares. The shares were sold on April 16, 2026 at a weighted average price of $2.26, with individual trades ranging from $2.25 to $2.28 per share, under a pre-arranged Rule 10b5-1 trading plan.

How many Milestone Pharmaceuticals (MIST) shares does the CEO still hold after this sale?

After the reported sale, Joseph Oliveto holds 446,244 common shares directly. Before selling 36,500 shares, his position was higher, so this filing shows a partial reduction of his holdings while he remains a substantial shareholder in the company.

At what prices were the Milestone Pharmaceuticals (MIST) shares sold in this Form 4?

The reported weighted average sale price was $2.26 per share. Footnote disclosure explains that the 36,500 shares were sold in multiple transactions at prices ranging from $2.25 to $2.28 per share, with the CEO offering to provide detailed trade breakdowns on request.

Does this Milestone Pharmaceuticals (MIST) Form 4 involve derivative securities or only common shares?

This Form 4 discloses a transaction only in common shares. The reported activity is a non-derivative open-market sale of 36,500 common shares, and the derivative section shows no remaining derivative positions in this specific filing excerpt.

How large is the CEO’s reported sale relative to his Milestone Pharmaceuticals (MIST) holdings?

The CEO sold 36,500 shares and reported 446,244 shares remaining. This indicates he disposed of only a portion of his stake, keeping a significant direct ownership position in Milestone Pharmaceuticals following the pre-planned transaction.