M33 Sells 6.7M TOIIW Shares at $3.09, Files Schedule 13D/A

Rhea-AI Filing Summary

Amendment No. 4 to Schedule 13D discloses that M33 Growth I LP, M33 Growth I GP LLC and TOI M, LLC (the Reporting Persons) amended their prior Schedule 13D to report a registered block trade executed on September 4, 2025. In that transaction M33 sold 6,018,168 shares and TOI M sold 681,832 shares of Oncology Institute, Inc. common stock at $3.09 per share. After accounting for holdings and warrants, the Reporting Persons report beneficial ownership of 9,290,838 shares, representing 9.79% of the company’s outstanding common stock based on 93,504,767 shares outstanding as of August 5, 2025. M33 LP entered a 180-day lock-up with B. Riley beginning September 4, 2025, subject to early termination if the closing price exceeds 140% of the sale price for four of five trading days. Other prior disclosures remain unchanged.

Positive

• Transparency: The Amendment clearly discloses the block trade details including share counts, sale price and registration under Form S-3.
• Lock-up in place: M33 LP agreed to a 180-day lock-up, which constrains near-term additional sales by the largest selling party.

Negative

• Large disposition: M33 LP sold 6,018,168 shares and TOI M sold 681,832 shares, increasing public float and potential selling pressure.
• Warrants included in ownership: 1,358,449 shares issuable upon exercise of warrants are counted in the 9.79% figure, which may differ from currently outstanding common stock influence.

Insights

Financial Analyst

TL;DR Significant registered sale reduced holdings but Reporting Persons still hold a near-10% stake and agreed to a time-limited lock-up.

The block trade liquidated a substantial portion of M33 LP's position at $3.09 per share, generating visible public distribution of shares under an S-3 registration. Beneficial ownership reported at 9.79% includes 1,358,449 shares issuable upon exercise of warrants, which inflates reported ownership compared with currently exercisable shares. The 180-day lock-up limits further immediate selling by M33 LP but contains a market-price escape clause tied to 140% of the sale price. For investors, the filing clarifies supply dynamics and near-term selling constraints without forward-looking commentary.

Corporate Governance Expert

TL;DR The amendment documents a large registered disposition and a standard underwriter lock-up with a market-based early termination.

The disclosure is procedural and consistent with governance norms for material holders executing registered secondary sales. The Reporting Persons expressly disclaim being a "group," and the filing notes no other arrangements or known third-party dividend or sale rights. The lock-up agreement with B. Riley is customary and time-limited, reducing immediate governance concerns about coordinated further sales while preserving an acceleration mechanism tied to stock price performance.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 4)

Oncology Institute, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

23343Q100

(CUSIP Number)

Gabriel Ling
c/o M33 Growth I LP, 888 Boylston Street, Suite 500
Boston, MA, 02199
6178770046

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

09/04/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 23343Q100

1

Name of reporting person

M33 Growth I LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 9,290,838.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 9,290,838.00

11

Aggregate amount beneficially owned by each reporting person

9,290,838.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.79 %

14

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person:

(1) This Schedule 13D is filed by M33 Growth I LP ("M33 LP"), M33 Growth I GP LLC ("M33 LLC") and TOI M, LLC ("TOI M" and, with M33 LP, collectively, the "Reporting Persons"). The Reporting Persons expressly disclaim status as a "group" for purposes of this Schedule 13D. (2) Consists of (i) 7,932,389 shares held by M33 LP and (ii) 1,358,449 shares issuable upon exercise of warrants to purchase shares of Common Stock for an exercise price of $1.1980 per share ("Warrants") held by M33 LP. M33 LLC serves as the sole general partner of M33 LP and, as such, M33 LLC possesses voting and dispositive power over the shares held by M33 LP, and may be deemed to have indirect beneficial ownership of the shares held by M33 LP. (3) This percentage is calculated based upon 93,504,767 shares of the Issuer's (as defined herein) common stock outstanding as of August 5, 2025, as disclosed in the Quarterly Report on Form 10-Q for the fiscal year ended June 30, 2025 filed by the Issuer with the Securities and Exchange Commission (the "SEC") on August 13, 2025 and the 1,358,449 shares issuable upon exercise of the Warrants.

SCHEDULE 13D

CUSIP No. 23343Q100

1

Name of reporting person

M33 Growth I GP LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 9,290,838.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 9,290,838.00

11

Aggregate amount beneficially owned by each reporting person

9,290,838.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.79 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person:

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a "group" for purposes of this Schedule 13D. (2) Consists of (i) 7,932,389 shares held by M33 LP and (ii) 1,358,449 shares issuable upon exercise of Warrants held by M33 LP. M33 LLC serves as the sole general partner of M33 LP and, as such, M33 LLC possesses voting and dispositive power over the shares held by M33 LP, and may be deemed to have indirect beneficial ownership of the shares held by M33 LP. (3) This percentage is calculated based upon 93,504,767 shares of the Issuer's (as defined herein) common stock outstanding as of August 5, 2025, as disclosed in the Quarterly Report on Form 10-Q for the fiscal year ended June 30, 2025 filed by the Issuer with the Securities and Exchange Commission (the "SEC") on August 13, 2025 and the 1,358,449 shares issuable upon exercise of the Warrants.

SCHEDULE 13D

CUSIP No. 23343Q100

1

Name of reporting person

TOI M, LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 590,892.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 590,892.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

590,892.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.63 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person:

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a "group" for purposes of this Schedule 13D. (2) This percentage is calculated based upon 93,504,767 shares of the Issuer's (as defined herein) common stock outstanding as of August 5, 2025, as disclosed in the Quarterly Report on Form 10-Q for the fiscal year ended June 30, 2025 filed by the Issuer with the Securities and Exchange Commission (the "SEC") on August 13, 2025.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.0001 per share
(b)	Name of Issuer: Oncology Institute, Inc.
(c)	Address of Issuer's Principal Executive Offices: 18000 Studebaker Road, Suite 800, Cerritos, CALIFORNIA , 90703.
Item 1 Comment: This Amendment No. 4 (the "Amendment") to Schedule 13D amends and supplements the Schedule 13D originally filed with the SEC on November 22, 2021, as amended by Amendment No. 1 filed with the SEC on July 12, 2022, Amendment No. 2 filed with the SEC on September 26, 2022, and Amendment No. 3 filed with the SEC on March 28, 2025 (as amended, the "Schedule 13D"), on behalf of M33 Growth I LP ("M33 LP"), M33 Growth I GP LLC ("M33 LLC") and TOI M, LLC ("TOI M" and, together with M33 LP and M33 LLC, collectively, the "Reporting Persons"), relates to the common stock, $0.001 par value ("Common Stock"), of The Oncology Institute, Inc., a Delaware corporation (the "Issuer" or "TOI"). The Items below amend and supplement the information disclosed under the corresponding Items of Schedule 13D as described below. Except as specifically provided herein, this Amendment does not modify any of the information previously reported in the Schedule 13D. Capitalized terms used but not defined herein shall have the meanings given to such terms in the Schedule 13D.
Item 3.	Source and Amount of Funds or Other Consideration
	On September 4, 2025, M33 sold 6,018,168 shares of Common Stock and TOI M sold 681,832 shares of Common Stock, in each case at a sale price of $3.09 per share (the "Sale Price"), in a transaction registered under the Securities Act of 1933, as amended, pursuant to an effective registration statement filed by the Issuer on Form S-3 (such transaction, the "Block Trade").
Item 4.	Purpose of Transaction
	Item 4 is hereby supplemented as follows: The information set forth in Item 3 of this Statement, as amended therein, is incorporated herein by reference.
Item 5.	Interest in Securities of the Issuer
(a)	Item 5 is hereby amended and restated as follows: (a) and (b) See Items 7-11 of the cover pages of this Statement, as amended, and Item 3 of the Statement.
(b)	Except as reported in this Statement, none of the Reporting Persons has effected any transactions in the Issuer's securities within the past 60 days.
(c)	No other person is known to the Reporting Persons to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock covered by this Statement.
(d)	Not applicable.
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	Item 6 is hereby supplemented as follows: The information set forth in Items 3 and 4 of this Statement is incorporated herein by reference. In connection with the Block Trade, M33 LP entered into a Lock-Up Agreement (the Lock-Up Agreement") with B. Riley Securities, Inc. ("B. Riley") pursuant to which M33 LP agreed not to sell or otherwise transfer any shares of Common Stock or securities convertible or exercisable for shares of Common Stock, subject to customary exceptions, for a 180 day period beginning on September 4, 2025 and ending on March 3, 2026 (the "Lock-Up Period"). The Lock-Up Period is subject to early termination if the closing price of the Common Stock exceeds 140% of the Sale Price for four out of five consecutive trading days. The foregoing description is qualified in its entirety by reference to the Lock-Up Agreement filed as Exhibit 1 to this Amendment.
Item 7.	Material to be Filed as Exhibits.
	Item 7 is hereby supplemented as follows: Lock-Up Agreement, dated August 21, 2025, by and between M33 Growth I LP and B. Riley Securities, Inc.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

M33 Growth I LP

Signature:	/s/ Gabriel Ling
Name/Title:	Gabriel Ling / Managing Member
Date:	09/05/2025

M33 Growth I GP LLC

Signature:	/s/ Gabriel Ling
Name/Title:	Gabriel Ling / Managing Member
Date:	09/05/2025

TOI M, LLC

Signature:	/s/ Gabriel Ling
Name/Title:	Gabriel Ling / Managing Member
Date:	09/05/2025

FAQ

What shares were sold in the Schedule 13D/A by M33 and TOI M for TOIIW?

M33 sold 6,018,168 shares and TOI M sold 681,832 shares in a registered block trade executed on September 4, 2025 at $3.09 per share.

How much of Oncology Institute, Inc. does the filing say the Reporting Persons beneficially own (TOIIW)?

The Reporting Persons report beneficial ownership of 9,290,838 shares, equal to 9.79% of common stock outstanding, which includes warrants convertible into 1,358,449 shares.

Does the filing include any lock-up restrictions after the block trade?

Yes. M33 LP entered into a 180-day lock-up with B. Riley beginning September 4, 2025 and ending March 3, 2026, subject to early termination if the closing price exceeds 140% of $3.09 for four of five consecutive trading days.

Are there any other transactions in the last 60 days reported in the filing?

Except for the transactions reported in this Amendment, the filing states that none of the Reporting Persons effected any transactions in the Issuer's securities within the past 60 days.

Does the filing indicate the Reporting Persons are acting as a group for TOIIW?

No. The Reporting Persons expressly disclaim status as a 'group' for purposes of this Schedule 13D.