[Form 4] Rush Street Interactive, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Bank of Montreal group discloses 6.51% passive stake in Mountain Lake Acquisition Corp. (MLACU)

Amendment No. 2 to Schedule 13G shows that, as of 30 Jun 2025, Bank of Montreal (BMO) and affiliates Bank of Montreal Holding Inc. and BMO Nesbitt Burns Inc. beneficially own 1,549,303 Class A ordinary shares of Mountain Lake Acquisition Corp., representing 6.51 % of the outstanding class.

• Sole voting & disposition: 69,303 shares held directly by Bank of Montreal.
• Shared voting & disposition: 1,480,000 shares jointly reported by all three entities.
• All reporting persons are Canadian federally chartered institutions; filing made under Rule 13d-1(b) indicating passive investment status.
• Shares are held in the ordinary course of business as prime broker for clients; the group certifies no intent to influence control.
• Certification signed by Managing Director Kathryn Cenac on 01 Aug 2025.

Insights

Securities Analyst

TL;DR: Passive 6.5 % holding; limited price impact, modest vote concentration.

The BMO group’s 1.55 M-share position crosses the 5 % threshold, requiring public disclosure. Because the stake is reported on Schedule 13G—rather than 13D—it signals a passive, non-activist posture. Institutional ownership now shifts modestly toward a single prime-broker platform, but the bulk (1.48 M) is client-directed, reducing the likelihood of coordinated voting. Overall market impact should be neutral: the filing neither adds strategic capital nor signals imminent divestiture. The information is still useful for liquidity analysis, indicating that roughly one-fourteenth of the float sits within BMO’s brokerage network.

Corporate Governance Expert

TL;DR: No governance implications; control intent expressly disclaimed.

The amendment reaffirms that BMO and its affiliates act solely as intermediary custodians. Their certification and 13G classification confirm absence of control ambitions, proxy contests, or board influence attempts. Therefore, governance risk remains unchanged. From a compliance standpoint, timely amendment filing demonstrates adherence to SEC beneficial-ownership rules.

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).

X

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^*

STETZ MATTIAS

(Last) (First) (Middle)

C/O RUSH STREET INTERACTIVE, INC.

900 N. MICHIGAN AVENUE, SUITE 950

(Street)

CHICAGO IL 60611

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Rush Street Interactive, Inc. [ RSI ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Operating Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/01/2025

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

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

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

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)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	08/01/2025		S(1)		30,000	D	$19.3039(2)	291,051	D
Class A Common Stock								205,448	I	By Spouse

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Shares were sold pursuant to a 10b5-1 Plan dated August 16, 2024.

2. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $18.29 to $19.595 per share. 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 at each separate price within the range set forth in this footnote.

Remarks:

	/s/ Kyle Sauers as Attorney-in-fact	08/01/2025
	** 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.

FAQ

How many Mountain Lake Acquisition Corp. shares does Bank of Montreal own?

The group reports beneficial ownership of 1,549,303 Class A shares.

What percentage of MLACU's Class A shares is held by BMO and affiliates?

Their stake represents 6.51 % of the outstanding Class A shares.

Does the Schedule 13G filing indicate any intent to influence control of MLACU?

No. The filing is on Schedule 13G and includes a certification that the securities are held passively and not for control purposes.

Why was this amendment to Schedule 13G filed?

Crossing the 5 % ownership threshold and subsequent ownership changes require disclosure; this is Amendment No. 2 updating those holdings.

What is the event date that triggered the filing requirement?

The relevant event date is 30 June 2025.